Update!

Sale 1: https://backpack.tf/profiles/76561198037791567#!/compare/1577836800/1578096000

https://backpack.tf/profiles/76561198207603105#!/compare/1577750400/1577836800

Appears to have been 19.

Sale 2: https://backpack.tf/profiles/76561198207603105#!/compare/1578096000/1578182400

https://backpack.tf/profiles/76561198317903441#!/compare/1578096000/1578182400

Sold for a duped Purple Energy Medic's Mountain Cap (28 keys)

Mini for the duped Mountain Cap:

Sale 1: https://backpack.tf/profiles/76561198035645252#!/compare/1576886400/1578441600

https://backpack.tf/profiles/76561198317903441#!/compare/1577491200/1577577600

Uhh, 30?

Sale 2: https://backpack.tf/profiles/76561198207603105#!/compare/1579996800/1580169600

https://backpack.tf/profiles/76561198022967421#!/compare/1579824000/1580169600

36 pure.

Clean one had lower seller so i minid the clean one, came to 28, taking that.

https://backpack.tf/suggestion/5e533ada6375d268782c606a

Sale 3: https://backpack.tf/profiles/76561198363380973#!/compare/1578528000/1578614400

https://backpack.tf/profiles/76561198131081286#!/compare/1578614400/1578700800

?

Sale 4: https://backpack.tf/profiles/76561198131081286#!/compare/1578528000/1578614400

https://backpack.tf/profiles/76561198339122801#!/compare/1578441600/1578614400

Use there/low

Sale 5: https://backpack.tf/profiles/76561198339122801#!/compare/1578614400/1578700800

https://backpack.tf/profiles/76561198095022965#!/compare/1578614400/1578700800

Used there.

Sale 6: https://marketplace.tf/items/tf2/30862;5;u15 - 69/1.78 = ~39

https://backpack.tf/item/5958621757

Sale 7: https://marketplace.tf/items/tf2/30862;5;u15 - 78.67/1.75 = ~45, buyout was 40: https://bot.tf/stats/listings/4PPK12N3

https://backpack.tf/item/5887038507

Sales: 28, 39 and 40. Classies: https://i.imgur.com/GnABTZt.png. Going with a range of 28-40.