That is..unfortunate.

Sales

Sale 1: Sold for 35 keys

https://backpack.tf/profiles/76561198192602363#!/compare/1599091200/1599177600

https://backpack.tf/profiles/76561198316610417#!/compare/1599091200/1599177600

Sale 2: Sold for 27 keys + 4 refined

https://backpack.tf/profiles/76561198985910282#!/compare/1598140800/1598227200

https://backpack.tf/profiles/76561198334429226#!/compare/1579046400/1598659200

27 keys~

Sale 3: Sold for 25 keys

https://backpack.tf/profiles/76561198080179568#!/compare/1598659200/1598745600

https://backpack.tf/profiles/76561198202133459#!/compare/1597536000/1599091200

This one was duped.

Sale 4: Untrace

https://backpack.tf/profiles/76561198081458286#!/compare/1598400000/1598486400

https://backpack.tf/profiles/76561198080179568#!/compare/1598400000/1598486400

Sale 5: Sold for 26 keys + 48 refined

https://backpack.tf/profiles/76561199015532580#!/compare/1594857600/1595203200

https://backpack.tf/profiles/76561198400562713#!/compare/1594512000/1596240000

27 keys~

Sale 6: Traced 1 key + 1.11 refined to quickbuyer

https://backpack.tf/profiles/76561198061108167#!/compare/1593993600/1594512000

https://backpack.tf/profiles/76561199015532580#!/compare/1593907200/1593993600

Sale 7: Sold for 27 keys

https://backpack.tf/profiles/76561198276044977#!/compare/1593216000/1593302400

https://backpack.tf/profiles/76561198061108167#!/compare/1591833600/1593216000

Sale 8: Sold with sweets and unusual for Scorching Flames Burning Bandana

https://backpack.tf/profiles/76561198252081728#!/compare/1599004800/1599091200

https://backpack.tf/profiles/76561198254822867#!/compare/1598918400/1599004800

If there was more added it'd be bulky, and if not, would be too high.

Sale 9: Sold for 25 keys + 3.77 refined

https://backpack.tf/profiles/76561198158197118#!/compare/1598918400/1599004800

https://backpack.tf/profiles/76561198252081728#!/compare/1598918400/1599004800

25 keys~

Sale 10: Sold for 25 keys

https://backpack.tf/profiles/76561198974703657#!/compare/1598918400/1599004800

https://backpack.tf/profiles/76561198158197118#!/compare/1598918400/1599004800

Sale 11: Sold for 25 keys

https://backpack.tf/profiles/76561198337734785#!/compare/1598832000/1598918400

https://backpack.tf/profiles/76561198974703657#!/compare/1598832000/1598918400

Sale 12: Traced 5 keys + 2 refined

https://backpack.tf/profiles/76561198412372767#!/compare/1593388800/1593993600

https://backpack.tf/profiles/76561198337734785#!/compare/1593302400/1593388800

Marketplace

https://marketplace.tf/items/tf2/379;5;u10

September

$64.99 on September 4 (64.99/1.83 = 36~)

https://manic.tf/keyprice/?at=2020-09-04

https://backpack.tf/item/388538433

Buyout was 28 keys: https://bot.tf/stats/listings/466QR1O2

Classifieds

https://gyazo.com/77c1db1cf2f05ba8e80200633fcdd7f6

Summary

Sales at 25, 25, 25, 25 (duped), 27, 27, 27, and 35.

Marketplace sales at 28.

Conclusion

35 is probably high with all these sales at lower, excluding 35.

Going with 25-28 here.