Using last month.

Sales 1-6:

Sold for $35, $39.39, $39.38, $26.05. $26.07, & $25.40 on marketplace.tf

https://marketplace.tf/items/463;5;u3003

http://manic.tf/keyprice/?at=2018-10-12 - $25.40 / $1.78 = 14.27 keys

http://manic.tf/keyprice/?at=2018-10-06 - $39.39 / $1.81 = 21.76 keys

http://manic.tf/keyprice/?at=2018-10-06 - $39.38 / $1.81 = 21.76 keys

http://manic.tf/keyprice/?at=2018-09-23 - $26.07 / $1.84 = 14.17 keys

http://manic.tf/keyprice/?at=2018-09-21 - $26.05 / $1.84 = 14.16 keys

http://manic.tf/keyprice/?at=2018-09-19 - $35 / $1.85 = 18.92 keys

X = 22 (2x)

X = 19

X = 14 (3x)

Sale 7:

Sold for 18 keys + 30 ref

Seller: https://backpack.tf/profiles/76561198334598690#!/compare/1538265600/1538352000

Buyer: https://backpack.tf/profiles/76561198312685638#!/compare/1538265600/1538352000

https://backpack.tf/item/2427696419

X = 19

Sale 8:

Sold for 18 keys + 20 ref?

Seller: https://backpack.tf/profiles/76561198305676157#!/compare/1538611200/1538697600

Buyer: https://backpack.tf/profiles/76561198336407054#!/compare/1538611200/1538697600

https://backpack.tf/item/3489270066

https://i.imgur.com/1akrULS.png

The exact amount of metal can be seen in the seller’s end, I’d say it’s safe to assume the sale is correct. Even if it isn’t, there is another sale at 19 anyways.

X = 19

Sale 9:

Sold for 18 keys

Seller: https://backpack.tf/profiles/76561198097271466#!/compare/1537920000/1538006400

Buyer: https://backpack.tf/profiles/76561198089074070#!/compare/1538006400/1538179200

https://backpack.tf/item/6412303839

X = 18

Sale 10:

Sold for 17 keys

Seller: https://backpack.tf/profiles/76561198312583107#!/compare/1539129600/1539216000

Buyer: https://backpack.tf/profiles/76561198030343929#!/compare/1539129600/1539216000

https://backpack.tf/item/2167215913

X = 17

Sale 11:

Sold for 17 keys

Seller: https://backpack.tf/profiles/76561198081213486#!/compare/1537747200/1537833600

Buyer: https://backpack.tf/profiles/76561198368150253#!/compare/1537833600/1537920000

https://backpack.tf/item/1803821700

X = 17

Sale 12:

Sold to a quickbuyer for 14 keys

Seller: https://backpack.tf/profiles/76561198218497692#!/compare/1537401600/1537488000

Buyer: https://backpack.tf/profiles/76561198097271466#!/compare/1537401600/1537488000

https://backpack.tf/item/6412303839

X = 14

Sale 13:

Sold for 14 keys

Seller: https://backpack.tf/profiles/76561198130990555#!/compare/1536969600/1537056000

Buyer: https://backpack.tf/profiles/76561198055562931#!/compare/1536883200/1537056000

https://backpack.tf/item/2916979627

X = 14

Sale 14:

Sold to a quickbuyer for 13 keys + 18 ref

Seller: https://backpack.tf/profiles/76561198368150253#!/compare/1537920000/1538352000

Buyer: https://backpack.tf/profiles/76561198097271466#!/compare/1538265600/1538352000

https://backpack.tf/item/1803821700

X = 13

Sale 15:

Sold for 13 keys + 10 ref

Seller: https://backpack.tf/profiles/76561198136342227#!/compare/1537488000/1537574400

Buyer: https://backpack.tf/profiles/76561198305676157#!/compare/1537488000/1537574400

https://backpack.tf/item/3489270066

https://i.imgur.com/1akrULS.png

Keys can be found on the buyer’s end.

X = 13

Other Sales:

https://backpack.tf/item/6977232016 (#1)

https://backpack.tf/item/5379246233 (#2)

https://backpack.tf/item/2916979627 (#3)

https://backpack.tf/item/2167215913 (#4)

https://backpack.tf/item/1803821700 (#5)

https://backpack.tf/item/6013554545 - marketplace

https://backpack.tf/item/6700373041 - marketplace

https://backpack.tf/item/2766243779 - marketplace

https://backpack.tf/item/2245256457 - gambled

#1

Untraceable

https://backpack.tf/profiles/76561198312583107#!/compare/1539129600/1539216000

https://i.imgur.com/1akrULS.png - Labelled as 17 keys, bought off the bot and instantly dumped on scrap.

#2

Untraceable

https://backpack.tf/profiles/76561198127214200#!/compare/1538006400/1538179200

https://backpack.tf/profiles/76561198044684270#!/compare/1537920000/1538006400

#3

Untraceable

https://backpack.tf/profiles/76561197963396109#!/compare/1536969600/1537056000

https://backpack.tf/profiles/76561198130990555#!/compare/1536969600/1537056000

#4

Untraceable

https://backpack.tf/profiles/76561198161953994#!/compare/1538956800/1539043200

https://backpack.tf/profiles/76561198312583107#!/compare/1538956800/1539043200

https://i.imgur.com/1akrULS.png

#5

Bulk for Morning Glory Ninja Hood

https://backpack.tf/profiles/76561198063054044#!/compare/1537315200/1537401600

https://backpack.tf/profiles/76561198081213486#!/compare/1537315200/1537401600

#6

Untraceable

https://backpack.tf/profiles/76561198305676157#!/compare/1537315200/1537401600

https://backpack.tf/profiles/76561198064490192#!/compare/1537574400/1537833600

Sale doesn’t even show up on bot.tf - https://i.imgur.com/1akrULS.png

Sellers:

https://i.imgur.com/0aEfqiv.png

https://i.imgur.com/NOjKLfq.png

https://backpack.tf/item/2167215913 - 17 keys

https://backpack.tf/item/1803821700 - 17 keys

https://backpack.tf/item/6171418999 - 18 keys

https://backpack.tf/item/2803370402 - 18 keys

https://backpack.tf/item/6700373041 - 19 keys

https://backpack.tf/item/2916979627 - 19 keys

https://backpack.tf/item/5376129327 - 21 keys

Sales at:

13 (2x)

14 (5x)

17 (2x)

18

19 (3x)

22 (2x)

The sales at 13 are around ~13.3 unrounded, and given the current buyers, it may be better to exclude 13. https://i.imgur.com/1924IQM.png

Definitely keeping 14, however.

There are 4 sellers cheaper than 19, some are a couple weeks unsold. Would be better to exclude 19 and higher.

Going with 14-18.