Sale 1:

Sold for 3 keys + ~2 keys in metal + ~1 key in items

Seller: https://backpack.tf/profiles/76561198347838878#!/compare/1526947200/1527033600

Buyer: https://backpack.tf/profiles/76561198153798099#!/compare/1526601600/1526947200

X = 6

Sale 2:

Sold for 5 keys + most wanted

https://i.imgur.com/24mIufG.png - B/O of ~5.5 keys (rounded to nearest .05) according to bot.tf

Seller: https://backpack.tf/profiles/76561198305676157#!/compare/1527206400/1527292800

Buyer: https://backpack.tf/profiles/76561198086592431#!/compare/1527292800/1527379200

X = 5.5 (Capped by B/O)

Sale 3:

Sold for 5 keys

Seller: https://backpack.tf/profiles/76561198054571897#!/compare/1526083200/1526169600

Buyer: https://backpack.tf/profiles/76561198055622215#!/compare/1526083200/1526169600

X = 5

Sales 4:

Sold for $14 and $10 on marketplace.tf

https://marketplace.tf/items/30614;5;u3004

$14 goes outdated soon and looks like it may be an outlier anyways so I’ll exclude it.

10/1.96 = ~5.1

X = 5

Sale 5:

Sold to a bot for 4 keys + 5 ref

Seller: https://backpack.tf/profiles/76561198035450661#!/compare/1526947200/1527033600

Buyer: https://backpack.tf/profiles/76561198305676157#!/compare/1526947200/1527033600

Bot.tf confirms: https://i.imgur.com/24mIufG.png

X = 4

Sale 6:

Bulk for Terror-Watt Surgeon’s Stahlhelm + items

Seller: https://backpack.tf/profiles/76561198055622215#!/compare/1526256000/1526342400

Buyer: https://backpack.tf/profiles/76561198355667850#!/compare/1526256000/1526342400

Sale 7:

Bulk for keys through auction

Seller: https://backpack.tf/profiles/76561198355667850#!/compare/1526342400/1526601600

Buyer: https://backpack.tf/profiles/76561198175440602#!/compare/1526169600/1526515200

Sale 8:

Bulk for things

Seller: https://backpack.tf/profiles/76561198175440602#!/compare/1527465600/1527552000

Buyer: https://backpack.tf/profiles/76561198293832300#!/compare/1527379200/1527552000

Sale 9:

Sold for Pro. KS Frontier Justice + Spelled Botkiller flamethrower

Seller: https://backpack.tf/profiles/76561198100773215#!/compare/1526169600/1526256000

Buyer: https://backpack.tf/profiles/76561198821887968#!/compare/1526169600/1526256000

spells are a big no-no

Sale 10:

Sold with junk for Purple Confetti Electric Escorter

Seller: https://backpack.tf/profiles/76561198188012822#!/compare/1525219200/1525305600

Buyer: https://backpack.tf/profiles/76561198118164985#!/compare/1525132800/1525305600

Too high if used here, too low if used there.

Sellers:

5 keys:

https://i.imgur.com/HR7wBfq.png

https://backpack.tf/item/3678656116

~5.8 keys:

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

https://backpack.tf/item/3926884766

7 keys:

https://i.imgur.com/J1YAUHL.png

https://backpack.tf/item/3832173543

8 keys:

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

https://backpack.tf/item/3903394270

http://www.tf2outpost.com/trade/29668635

9 keys:

https://i.imgur.com/qK2Oh8b.png

https://backpack.tf/item/5434116630

Sales at:

4

5 (2x)

5.5

6

4 seems low, excluding.

Not comfortable using the sale at 6, and given the cheaper sellers, it may be too high anyways. Excluding 6.

Going with 5-5.5.