Using last 2 months due to the abundance of sales here.

Sales 1-4:

Sold for $19.92, $19.93, $20, and $14 on marketplace.tf

https://marketplace.tf/items/30662;5;u98

https://backpack.tf/item/7020369859 - No outpost

https://backpack.tf/item/5480997148 - No outpost

Couldn’t find the other two.

http://manic.tf/keyprice/?at=2018-07-26 - $19.92 / $1.96 = 10.16 keys

http://manic.tf/keyprice/?at=2018-07-29 - $19.93 / $1.97 = 10.12 keys

http://manic.tf/keyprice/?at=2018-08-01 - $20 / $1.94 = 10.31 keys

http://manic.tf/keyprice/?at=2018-08-02 - $14 / $1.93 = 7.25 keys

X = 10 (3x)

X = 7.5

Sale 5:

Sold for 10 keys

Seller: https://backpack.tf/profiles/76561198138135050#!/compare/1534636800/1534723200

Buyer: https://backpack.tf/profiles/76561198277421153#!/compare/1534550400/1534723200

https://backpack.tf/item/6750386452

X = 10

Sale 6:

Sold for Showstopper Most Wanted (6.25) + 4 keys

http://www.tf2outpost.com/trade/29749099 - B/O of 10

Seller: https://backpack.tf/profiles/76561198177327822#!/compare/1534809600/1535241600

Buyer: https://backpack.tf/profiles/76561198076191312#!/compare/1534982400/1535068800

X = 10 (Capped by B/O)

Sale 7:

Sold for 9 keys

Seller: https://backpack.tf/profiles/76561198263938120#!/compare/1532304000/1532649600

Buyer: https://backpack.tf/profiles/76561198156461967#!/compare/1532476800/1532649600

https://backpack.tf/item/5611434088

X = 9

Sale 8:

Sold for 9 keys + 7 ref

Seller: https://backpack.tf/profiles/76561198311498888#!/compare/1530835200/1530921600

Buyer: https://backpack.tf/profiles/76561198732913833#!/compare/1530835200/1531440000

https://backpack.tf/item/6845194780

Nothing matches, but I can guarantee the keys were obtained from scrap after the buyer sold their unusual(s) there, then bought the hat before their backpack was scanned with the keys.

X = 9

Sale 9:

Sold for 8 keys + ~1 key in items

Seller: https://backpack.tf/profiles/76561198061275415#!/compare/1533686400/1533772800

Buyer: https://backpack.tf/profiles/76561198193646205#!/compare/1533686400/1533772800

https://backpack.tf/item/6845194780

Keys spent on the other HFoHA before backpack was scanned with them in it.

X = 9

Sale 10:

Sold for 8 keys?

Seller: https://backpack.tf/profiles/76561198312583107#!/compare/1531785600/1531872000

Buyer: https://backpack.tf/profiles/76561198368281005#!/compare/1531785600/1531872000

https://backpack.tf/item/5611434088

https://gyazo.com/b0e2ca450419fb1df2688fde2706df3e

7 keys match on the buyer’s end, though I doubt bot.tf is incorrect here.

X = 8

Sale 11:

Sold for 8 keys + possibly some metal

Seller: https://backpack.tf/profiles/76561198035805524#!/compare/1534118400/1534204800

Buyer: https://backpack.tf/profiles/76561198177327822#!/compare/1534204800/1534550400

https://backpack.tf/item/4371694269

X = 8

Sale 12:

Sold for 8 keys

Seller: https://backpack.tf/profiles/76561198083603889#!/compare/1534982400/1535068800

Buyer: https://backpack.tf/profiles/76561198205153083#!/compare/1534982400/1535068800

https://backpack.tf/item/4371694269

X = 8

Sale 13:

Bought from scrap.tf for 8 keys + a small amount of metal

Seller: https://backpack.tf/profiles/76561198135388328#!/compare/1534291200/1534377600

Buyer: https://backpack.tf/profiles/76561198097649824#!/compare/1534291200/1534550400

https://backpack.tf/item/4197113921

X = 8

Sale 14:

Sold for 8 keys

Seller: https://backpack.tf/profiles/76561198312583107#!/compare/1531173600/1531260000

Buyer: https://backpack.tf/profiles/76561198202476873#!/compare/1530230400/1531267200

https://gyazo.com/b0e2ca450419fb1df2688fde2706df3e

https://backpack.tf/item/6861078491

X = 8

Sale 15:

Dumped on scrap.tf for 7 keys + ~0.5 keys in metal

Seller: https://backpack.tf/profiles/76561198163912348#!/compare/1534550400/1534896000

Buyer: https://backpack.tf/profiles/76561198135388328#!/compare/1534809600/1534896000

https://backpack.tf/item/6750386452

X = 7.5

Sale 16:

Sold to scrap for 7 keys + ~0.5 keys in metal

Seller: https://backpack.tf/profiles/76561198732913833#!/compare/1530835200/1531440000

Buyer: https://backpack.tf/profiles/76561198135388328#!/compare/1531353600/1531440000

https://backpack.tf/item/6845194780

X = 7.5

Sale 17:

Sold to a quickbuyer for 7 keys + ~0.5 keys in metal

Seller: https://backpack.tf/profiles/76561198166855771#!/compare/1533945600/1534032000

Buyer: https://backpack.tf/profiles/76561198337734785#!/compare/1533945600/1534032000

https://backpack.tf/item/6810816398

X = 7.5

Sale 18:

Sold to a bot for 7 keys + 8 ref

Seller: https://backpack.tf/profiles/76561198146565451#!/compare/1531699200/1531785600

Buyer: https://backpack.tf/profiles/76561198312583107#!/compare/1531699200/1531785600

https://backpack.tf/item/5611434088

https://gyazo.com/b0e2ca450419fb1df2688fde2706df3e

X = 7

Other Sales:

https://backpack.tf/item/6866406439 - mannco.trade bots

https://backpack.tf/item/6266297137 - no

https://backpack.tf/item/4851586059 - Dumped on tradeit.gg

#1

Untraceable, dumped on scrap.tf

https://backpack.tf/profiles/76561197964546925#!/compare/1532908800/1532995200

https://backpack.tf/profiles/76561198135388328#!/compare/1532908800/1532995200

https://backpack.tf/item/7020369859

#2

Untraceable, bought from scrap.tf

https://backpack.tf/profiles/76561198135388328#!/compare/1532908800/1532995200

https://backpack.tf/profiles/76561198014728963#!/compare/1532908800/1532995200

https://backpack.tf/item/7020369859

#3

Untraceable, the “buyer” here is probably a gambling bot or something

https://backpack.tf/profiles/76561198014728963#!/compare/1532908800/1532995200

https://backpack.tf/profiles/76561198197481041#!/compare/1532995200/1533081600

https://backpack.tf/item/7020369859

#4

Untraceable

https://backpack.tf/profiles/76561198197481041#!/compare/1533081600/1533168000

https://backpack.tf/profiles/76561198018101085#!/compare/1533081600/1533168000

https://backpack.tf/item/7020369859

#5

Untraceable

https://backpack.tf/profiles/76561198018101085#!/compare/1534291200/1534464000

https://backpack.tf/profiles/76561198392000113#!/compare/1534204800/1534377600

https://backpack.tf/item/7020369859

#6

Untraceable, bought from scrap.tf involving a green confetti l’inspecteur

https://backpack.tf/profiles/76561198135388328#!/compare/1531353600/1531440000

https://backpack.tf/profiles/76561198102291547#!/compare/1531353600/1531440000

https://backpack.tf/item/6845194780

Even if this sale is fully traceable, it would be better to just stick with pure sales here.

#7

Untraceable, only 6 keys and some metal match, though I’m certain more was involved.

https://backpack.tf/profiles/76561198102291547#!/compare/1533081600/1533600000

https://backpack.tf/profiles/76561198061275415#!/compare/1533081600/1533168000

https://backpack.tf/item/6845194780

Sold to a quickbuyer anyways.

#8

SCM

https://backpack.tf/profiles/76561198237157560#!/compare/1531526400/1531785600

https://backpack.tf/profiles/76561198007206529#!/compare/1531958400/1532131200

https://backpack.tf/item/6812326969

#9

Weird bulk sale for spelled Collector’s Eureka Effect

https://backpack.tf/profiles/76561198068392923#!/compare/1533772800/1533859200

https://backpack.tf/profiles/76561198026194410#!/compare/1533772800/1533859200

https://backpack.tf/item/6810816398

#10

Transferred to broker?

https://backpack.tf/profiles/76561198026194410#!/compare/1533945600/1534032000

https://backpack.tf/profiles/76561198166855771#!/compare/1533945600/1534032000

https://backpack.tf/item/6810816398

Leeches from the sale above this one, the spelled collector’s eureka effect came from the buyer here, which leads me to believe that it was being brokered.

#11

Raffled away

https://backpack.tf/profiles/76561197995932160#!/compare/1531440000/1533081600

https://backpack.tf/item/6750386452

#12

Dumped on mannco.trade

https://backpack.tf/profiles/76561198202336859#!/compare/1533168000/1533254400

https://backpack.tf/item/6750386452

#13

Untraceable, probably went to a buy order

https://backpack.tf/profiles/76561198275971013#!/compare/1533945600/1534032000

https://backpack.tf/profiles/76561198054758757#!/compare/1533945600/1534032000

https://backpack.tf/item/6750386452

#14

Untraceable, only 2 keys match

https://backpack.tf/profiles/76561198054758757#!/compare/1534550400/1534636800

https://backpack.tf/profiles/76561198138135050#!/compare/1534464000/1534636800

https://backpack.tf/item/6750386452

#15

Bulk-ish to scrap for a Purple Confetti Bootleg Base Metal Billycock

https://backpack.tf/profiles/76561198277421153#!/compare/1534723200/1534982400

https://backpack.tf/profiles/76561198135388328#!/compare/1534809600/1534896000

https://backpack.tf/item/6750386452

#16

Untraceable, bought off scrap.tf

https://backpack.tf/profiles/76561198135388328#!/compare/1534809600/1534896000

https://backpack.tf/profiles/76561198163912348#!/compare/1534550400/1534896000

https://backpack.tf/item/6750386452

NearID shows 10 keys involved, but scrap doesn’t ask for full bp.tf price for unusuals, so something’s up.

#17

Untraceable, bought off scrap.tf. Only 3 keys match.

https://backpack.tf/profiles/76561198135388328#!/compare/1534809600/1534896000

https://backpack.tf/profiles/76561198061897755#!/compare/1534723200/1534982400

https://backpack.tf/item/6750386452

#18

Untraceable, sold to a quickbuyer

https://backpack.tf/profiles/76561198061897755#!/compare/1534982400/1535068800

https://backpack.tf/profiles/76561198337734785#!/compare/1534896000/1534982400

https://backpack.tf/item/6750386452

#19

Untraceable. 17 keys match on the buyer’s end, but that’s most likely because they bought 2 unusuals from the same buyer. Seller’s end shows some metal was involved, so it may be better to just ignore this sale.

https://backpack.tf/profiles/76561198337734785#!/compare/1535241600/1535328000

https://backpack.tf/profiles/76561198353396836#!/compare/1534723200/1535328000

https://backpack.tf/item/6750386452

#20

Untraceable

https://backpack.tf/profiles/76561198368281005#!/compare/1531785600/1531872000

https://backpack.tf/profiles/76561198439812057#!/compare/1531785600/1531872000

https://backpack.tf/item/5611434088

#21

Bulk

https://backpack.tf/profiles/76561198439812057#!/compare/1531785600/1531872000

https://backpack.tf/profiles/76561198351777058#!/compare/1531612800/1531872000

https://backpack.tf/item/5611434088

#22

Bulk for Kill-a-Watt Private Eye

https://backpack.tf/profiles/76561198351777058#!/compare/1531872000/1531958400

https://backpack.tf/profiles/76561198263938120#!/compare/1531612800/1531958400

https://backpack.tf/item/5611434088

#23

Untraceable, most likely not a real sale

https://backpack.tf/profiles/76561197970669109#!/compare/1534723200/1534896000

https://backpack.tf/profiles/76561198086096507#!/compare/1516579200/1534896000

https://backpack.tf/item/5480997148

#24

Untraceable, dumped on scrap.tf

https://backpack.tf/profiles/76561198119614354#!/compare/1528243200/1534636800

https://backpack.tf/profiles/76561198135388328#!/compare/1533427200/1533513600

https://backpack.tf/item/4421232746

#25

Untraceable, bought off scrap.tf

https://backpack.tf/profiles/76561198135388328#!/compare/1533427200/1533513600

https://backpack.tf/profiles/76561198149824582#!/compare/1533513600/1533686400

https://backpack.tf/item/4421232746

#26

Given the nature of the compare link, probably scammed and dumped on scrap.

https://backpack.tf/profiles/76561198052895830#!/compare/1535328000/1535587200

https://backpack.tf/profiles/76561198135388328#!/compare/1535414400/1535500800

https://backpack.tf/item/4376227607

#27

Untraceable, bought off scrap.tf

https://backpack.tf/profiles/76561198135388328#!/compare/1535414400/1535500800

https://backpack.tf/profiles/76561198090147535#!/compare/1535414400/1535500800

https://backpack.tf/item/4376227607

#28

Probably gambled or something

https://backpack.tf/profiles/76561198135388328#!/compare/1535414400/1535500800

https://backpack.tf/profiles/76561198090147535#!/compare/1535414400/1535500800

https://backpack.tf/item/4376227607

#29

Probably gambled again

https://backpack.tf/profiles/76561198412941346#!/compare/1535500800/1535587200

https://backpack.tf/profiles/76561198065761144#!/compare/1535500800/1535587200

https://backpack.tf/item/4376227607

#30

Untraceable buyer was either unscanned or private.

https://backpack.tf/profiles/76561198075248548#!/compare/1532822400/1532995200

https://backpack.tf/item/4371694269

#31

Untraceable, bought off scrap.tf

https://backpack.tf/profiles/76561198135388328#!/compare/1534032000/1534118400

https://backpack.tf/profiles/76561198035805524#!/compare/1534118400/1534204800

https://backpack.tf/item/4371694269

#32

Untraceable

https://backpack.tf/profiles/76561198076191312#!/compare/1534982400/1535068800

https://backpack.tf/profiles/76561198083603889#!/compare/1534982400/1535068800

https://backpack.tf/item/4371694269

#33

Untraceable. Sold to scrap.tf

https://backpack.tf/profiles/76561198205153083#!/compare/1534982400/1535068800

https://backpack.tf/profiles/76561198135388328#!/compare/1534982400/1535068800

https://backpack.tf/item/4371694269

7 keys match, but I can guarantee metal was involved.

#34

Scrap.tf sale involving other unusuals.

https://backpack.tf/profiles/76561198135388328#!/compare/1535068800/1535155200

https://backpack.tf/profiles/76561198297054985#!/compare/1533859200/1535241600

https://backpack.tf/item/4371694269

#35

Untraceable, sold to scrap.tf

https://backpack.tf/profiles/76561198290106246#!/compare/1533081600/1533168000

https://backpack.tf/profiles/76561198135388328#!/compare/1532995200/1533081600

https://backpack.tf/item/4197113921

7 keys match, again, I’m sure metal was involved.

#36

Untraceable, bought off scrap.tf

https://backpack.tf/profiles/76561198135388328#!/compare/1532995200/1533081600

https://backpack.tf/profiles/76561198163491001#!/compare/1532995200/1533081600

https://backpack.tf/item/4197113921

#37

Untraceable

https://backpack.tf/profiles/76561198027256223#!/compare/1534032000/1534118400

https://backpack.tf/profiles/76561198027256223#!/compare/1533254400/1533340800

https://backpack.tf/item/4197113921

#38

Untraceable, sold to scrap.tf

https://backpack.tf/profiles/76561198064714626#!/compare/1533945600/1534032000

https://backpack.tf/profiles/76561198135388328#!/compare/1533945600/1534032000

Sellers:

https://gyazo.com/00ee065cbc5603e08b6dc1abafd45dc3

https://backpack.tf/item/6810816398 - ~8.73 keys

https://backpack.tf/item/6266297137 - ~8.76 keys

https://backpack.tf/item/4197113921 - 9 keys

https://backpack.tf/item/7037025616 - ~9.67 keys

https://backpack.tf/item/6001437333 - 10 keys

Sales at:

7

7.5 (4x)

8 (5x)

9 (3x)

10 (5x)

7 is low, excluding 7.

On top of the 7.5 sales being a common trading point, if all the scrap.tf purchases were traceable, this would probably be twice as common. Keeping 7.5.

10 may have a 3 month-old seller at that price, but sales at 10 are abundant, and if we were to keep 7.5, it would be fair to include 10 as well.

Going with 7.5-10.