The bat has rabies

https://backpack.tf/item/11318511154

1)Sold for a orbiting fire respectless rubber glove and some keys

https://backpack.tf/profiles/76561198243403578#!/compare/1646265600/1646352000

https://backpack.tf/profiles/76561198135388328#!/compare/1646265600/1646352000

2)Sold for 15 keys

https://backpack.tf/profiles/76561198135388328#!/compare/1646611200/1646697600

https://backpack.tf/profiles/76561198835804641#!/compare/1646611200/1646697600

3)Untrace

https://backpack.tf/profiles/76561198835804641#!/compare/1646697600/1646784000

https://backpack.tf/profiles/76561198213272097#!/compare/1646611200/1646697600

4)Seems like it was 1:1 for a Terror-Watt Tower Piller of Hats

https://backpack.tf/profiles/76561198213272097#!/compare/1646697600/1646784000

https://backpack.tf/profiles/76561198042000402#!/compare/1645574400/1646784000

https://backpack.tf/item/9770833649

5)Sold for 13 keys 0.88 ref (13 keys)

https://backpack.tf/profiles/76561198135388328#!/compare/1641513600/1641600000

https://backpack.tf/profiles/76561198097984345#!/compare/1641513600/1641600000

6)Untrace

https://backpack.tf/profiles/76561198097984345#!/compare/1641600000/1641686400

https://backpack.tf/profiles/76561198862682995#!/compare/1641513600/1641600000

7)Sold for 14 keys

https://backpack.tf/profiles/76561198862682995#!/compare/1642896000/1642982400

https://backpack.tf/profiles/76561198049171595#!/compare/1642464000/1642982400

Skipping rest since they're just marketplace bots

https://backpack.tf/item/8527495906

8)Untrace

https://backpack.tf/profiles/76561198311241435#!/compare/1642377600/1642464000

https://backpack.tf/profiles/76561198262832666#!/compare/1632441600/1644451200

Then moved to mannco.store

9)Sold for 26.30 USD on 3/6/2022

https://mannco.store/item/440-bubbling-unusual-bat-hat

Keys that day were 1.62 USD

https://mannco.store/item/440-mann-co-supply-crate-key

26.30 / 1.62 = 16.2345 = 16 keys

https://backpack.tf/item/8292969620

10)Sold for 15 keys

https://backpack.tf/profiles/76561198364363089#!/compare/1641772800/1641945600

https://backpack.tf/profiles/76561198112466064#!/compare/1641686400/1641772800

Got moved to mannco.store

Final sales at 13, 14, 15, 15, 16 keys

No reason to exclude any of the sales, taking 13 -16 keys