Item 1: https://backpack.tf/item/3949667431

Sale 1:

https://backpack.tf/profiles/76561198021055079#!/compare/1770422400/1770508800

https://backpack.tf/profiles/76561198108388792#!/compare/1770422400/1770508800

Sold for 56 keys pure (ID 16704663747)

Sale 2:

https://backpack.tf/profiles/76561198153336088#!/compare/1768867200/1768953600

https://backpack.tf/profiles/76561198021055079#!/compare/1768867200/1768953600

Bulk for Green Black Hole Chieftain's Challenge

MP Sale, keeping all of them down the bottom in 1.

Item 2: https://backpack.tf/item/7440545284 - Just moved to MPTF

Item 3: https://backpack.tf/item/11644451108

Sale 3:

https://backpack.tf/profiles/76561198152612559#!/compare/1767139200/1767225600

https://backpack.tf/profiles/76561198833734475#!/compare/1767139200/1767225600

Bulk sale for a HH The Essential Accessories

Then moved to MPTF

Item 4: https://backpack.tf/item/8373703709

Sale 4:

https://backpack.tf/profiles/76561199084784906#!/compare/1769040000/1769126400

https://backpack.tf/profiles/76561198082529946#!/compare/1768953600/1769126400

Sold for 57 keys pure (ID 16650608528)

Then the rest of the movements were just between quicksell bots

Item 5: https://backpack.tf/item/13407181085 - Moved to MPTF

Sale 5 and 6:

https://marketplace.tf/items/tf2/1157;5;u3121

Sold for $129.99 on the 18th of Dec & $149.99 on the 23rd of Dec

Keys were $1.83 on both the 18th and 23rd - https://marketplace.tf/items/tf2/5021;6

18th sale (129.99/1.83) = 71.03 (Rounding down to 71 keys)

23rd sale (149.99/1.83) = 81.9 (Rounding up to 82 keys)

//

Sellers:

BPTF - None

MPTF - https://marketplace.tf/items/tf2/1157;5;u3121 - 2 @ $159.99

STN - https://stntrading.eu/item/tf2/Unusual+Pastel+Trance+Taunt%3A+Kazotsky+Kick - None

SCM - https://steamcommunity.com/market/listings/440/Unusual%20Taunt%3A%20Kazotsky%20Kick?filter=Pastel+Trance - https://imgur.com/a/WSFOb7s - 1 @ $195.38AUD (~60)

Sale(s):

56, 57, 71, 82

Considering the seller at 60 I wouldn't want to put the two MP sales in the range. MP sales also tend to be more inflated than pure.

Going with 56 - 57 keys due to them being the pure key sales