Using last month.

Sales 1 & 2:

Sold for $22.99 and $12.02 on marketplace.tf

https://marketplace.tf/items/1110;5;u3004

12.02 would’ve gone to a buy order, excluding.

22.99/1.95 = ~11.8

X = 12

Sale 3:

Sold for 9 keys + 26 ref

Seller: https://backpack.tf/profiles/76561198305676157#!/compare/1527552000/1527638400

Buyer: https://backpack.tf/profiles/76561198079516052#!/compare/1527638400/1527724800

Bot.tf confirms: https://i.imgur.com/2pvSQ7Z.png

X = 10

Sale 4:

Sold to a bot for 8 keys + 1 scrap

Seller: https://backpack.tf/profiles/76561197960443103#!/compare/1527120000/1527465600

Buyer: https://backpack.tf/profiles/76561198305676157#!/compare/1527379200/1527465600

Bot.tf confirms: https://i.imgur.com/2pvSQ7Z.png

X = 8

Sale 5:

Bulk for Grail Mannrobics

Seller: https://backpack.tf/profiles/76561198047154265#!/compare/1527984000/1528070400

Buyer: https://backpack.tf/profiles/76561198324326065#!/compare/1527984000/1528070400

Sellers:

10 keys:

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

https://backpack.tf/item/5185886433

https://backpack.tf/item/4315674462

11 keys:

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

https://backpack.tf/item/5966509947

14 keys:

https://i.imgur.com/x9JV2Bn.png

https://backpack.tf/item/5579808601

29 keys:

https://i.imgur.com/URd6DvD.png

https://backpack.tf/item/2738431941

Sales at:

8

10

12

8 seems low and 12 seems high, including both should cancel each other out.

Going with 8-12.

sold for 11 keys

https://backpack.tf/profiles/76561198334598690#!/compare/1528675200/1528761600

https://backpack.tf/profiles/76561198102861548#!/compare/1528416000/1528761600

https://i.imgur.com/rPHkimT.png - bot.tf confirms

Sold for Whirlwind Zoomin' Broom (10.5) + RPS (~0.5)

https://backpack.tf/profiles/76561198057155071#!/compare/1529280000/1529798400

X = 11