Unfortunate (for me), but thanks K1ng for the new sale!

Sales

Sale 1: Untrace

https://backpack.tf/profiles/76561198137936969#!/compare/1600041600/1600300800

https://backpack.tf/profiles/76561198188093413#!/compare/1600214400/1600300800

Sale 2: Bulk

https://backpack.tf/profiles/76561198349348738#!/compare/1598140800/1600387200

https://backpack.tf/profiles/76561198146265553#!/compare/1599782400/1599868800

Sale 3: Sold for 27 keys

https://backpack.tf/profiles/76561198883208541#!/compare/1597276800/1597881600

https://backpack.tf/profiles/76561198349348738#!/compare/1597190400/1597276800

Sale 4: Sold with Blizzardy Storm A Hat to Kill For for Starstorm Slumber Galvanized Gibus

https://backpack.tf/profiles/76561198850003204#!/compare/1594857600/1596153600

https://backpack.tf/profiles/76561198883208541#!/compare/1595376000/1596153600

Better used for the Gibus.

Sale 5: Sold for 21 keys~

https://backpack.tf/profiles/76561198845530783#!/compare/1600300800/1600387200

https://backpack.tf/profiles/76561198394160901#!/compare/1600128000/1600387200

Sale 6: Sold for Sparkling Lights Spiky Viking (10.5 keys) + 10 keys

https://backpack.tf/profiles/76561198059474977#!/compare/1600214400/1600300800

https://backpack.tf/profiles/76561198845530783#!/compare/1600300800/1600387200

10.5 + 10 = 21 keys~

Spiky Viking: https://backpack.tf/suggestion/5f666adea46a340f68586bfe

Check comments.

Sale 7: Sold with 4 keys for..?

https://backpack.tf/profiles/76561198198440035#!/compare/1599955200/1600041600

https://backpack.tf/profiles/76561198059474977#!/compare/1599955200/1600041600

Sale 8: Traced 2.55 keys in items

https://backpack.tf/profiles/76561198120672630#!/compare/1599955200/1600041600

https://backpack.tf/profiles/76561198198440035#!/compare/1599955200/1600041600

Sale 9: Untrace

https://backpack.tf/profiles/76561198234535544#!/compare/1599782400/1599868800

https://backpack.tf/profiles/76561198120672630#!/compare/1599782400/1599868800

Sale 10: Sold for 26 keys (count the keys in second comparison)

https://backpack.tf/profiles/76561198135015291#!/compare/1599696000/1599782400

https://backpack.tf/profiles/76561198234535544#!/compare/1599609600/1599782400

Sale 11: Untrace

https://backpack.tf/profiles/76561198040186479#!/compare/1599177600/1599264000

https://backpack.tf/profiles/76561198135015291#!/compare/1599264000/1599523200

Sale 12: Sold for a C9 Hermes (buyers at ~15) + ~7 keys

https://backpack.tf/profiles/76561198836910437#!/compare/1600905600/1600992000

https://backpack.tf/profiles/76561198188093413#!/compare/1600905600/1600992000

Buyout was 22 keys so regardless it would cap.

Marketplace

https://marketplace.tf/items/tf2/30862;5;u29

August

$33 on August 21 (33/1.79 = 18~)

https://manic.tf/keyprice/?at=2020-08-21

https://backpack.tf/item/5872126932

September

$44.99 on September 17 (44.99/1.84 = 24~)

https://manic.tf/keyprice/?at=2020-09-17

https://marketplace.tf/items/tf2/5021;6

Listings during the time: https://bot.tf/stats/listings/Y79WVQL9

Classifieds

https://gyazo.com/0211a05d7e80caff3b5df8a90671257b

Summary

Sales at 21, 21, 22, 26, and 27.

Marketplace sales at 18 and 24.

Conclusion

18 is under buyers, excluding.

3 sellers at around 21 and 22, showing that the sales at 24, 26, and 27 are high.

Going with 21-22 here.