3rd times the charm, right?

Most sales where for the taunt before it was unusualified.

Sale 1:

Sold for Circling Peace Topi (11) + Midnight Disco Fever (13) = 24 total

https://backpack.tf/profiles/76561198273700921#!/compare/1517529600/1517702400

Sale 2:

Sold for Max's (rounding to 20) (refined was crafted into hats)

https://backpack.tf/profiles/76561198079869886#!/compare/1517097600/1517875200

Sale 3:

Sold for Strange Blizzardy Private Eye (Mini at 17)

https://backpack.tf/profiles/76561198410145031#!/compare/1517529600/1517616000

Sale 4:

Sold for Ghastly Ghosts Deep Fried (Mini at 18)

https://backpack.tf/profiles/76561198273700921#!/compare/1518048000/1518134400

Sale 5:

Sold with 2 Pure and 21 Ref, 44 Ref in sweets for a Misty Skull Football (In-date at 30) 30 - 3 (Rounded sweets and Ref) = 27 Keys

https://backpack.tf/profiles/76561198079869886#!/compare/1516579200/1516838400

One sold on Marketplace.tf for $49.98

49.98 ÷ 1.90 = 26.31 rounding to 26 keys

https://imgur.com/a/xmVaU

Mini for Strange Private Eye:

17 Pure

https://backpack.tf/profiles/76561198410145031#!/compare/1517616000/1517788800

Mini for Deep Fried:

Sold on Marketplace for $35 ÷ 1.9 = 18.42, rounding to 18 keys

https://imgur.com/a/rBTpP

Quite a big range but this should work