Resuggestion, thanks to K1ng for the info!

Sale 1:

https://backpack.tf/profiles/76561198062365679#!/compare/1562284800/1563235200

https://backpack.tf/profiles/76561198119340076#!/compare/1562889600/1563062400

Sold for 22 keys

Sale 2:

https://backpack.tf/profiles/76561198119340076#!/compare/1563580800/1563667200

https://backpack.tf/profiles/76561198319589832#!/compare/1563580800/1563667200

Untrace

Sale 3:

https://backpack.tf/profiles/76561198319589832#!/compare/1563580800/1563667200

https://backpack.tf/profiles/76561198802802073#!/compare/1563667200/1563753600

Sold for GE Snaggle(25)

Sale 4:

https://backpack.tf/profiles/76561198802802073#!/compare/1563667200/1563753600

https://backpack.tf/profiles/76561198213234076#!/compare/1563667200/1563753600

Sold for Miami Belgian + ~4 keys in sweets

use there

Sale 5:

https://backpack.tf/profiles/76561198213234076#!/compare/1563667200/1563753600

https://backpack.tf/profiles/76561198074971373#!/compare/1563667200/1563753600

Sold for 22 keys

Sale 6:

https://backpack.tf/profiles/76561198388065024#!/compare/1561161600/1561248000

https://backpack.tf/profiles/76561198091145584#!/compare/1561161600/1561248000

Bulky / untrace

Sale 7:

https://backpack.tf/profiles/76561198091145584#!/compare/1562112000/1562198400

https://backpack.tf/profiles/76561198349886701#!/compare/1562198400/1562284800

QS

Sale 8:

https://backpack.tf/profiles/76561198349886701#!/compare/1564099200/1564272000

https://backpack.tf/profiles/76561198021055079#!/compare/1564185600/1564272000

Sold for keys

Sale 9:

https://backpack.tf/profiles/76561198021055079#!/compare/1564444800/1564531200

https://backpack.tf/profiles/76561198142482594#!/compare/1564531200/1564790400

Sold for Steaming Coldsnap + ~6 keys in sweets

use there

Sale 10:

https://backpack.tf/profiles/76561198142482594#!/compare/1566000000/1567728000

https://backpack.tf/profiles/76561198031743044#!/compare/1565913600/1566000000

Sold for Max Head(~22 keys)

Sale 11:

https://backpack.tf/profiles/76561198220098345#!/compare/1568073600/1568419200

https://backpack.tf/profiles/76561198084708697#!/compare/1568332800/1568419200

Bulk

Sale 12:

https://backpack.tf/profiles/76561198031743044#!/compare/1565913600/1566000000

https://backpack.tf/profiles/76561198394877897#!/compare/1565913600/1566000000

Sold for 18 keys

sale 13:

https://backpack.tf/profiles/76561198394877897#!/compare/1567123200/1567209600

https://backpack.tf/profiles/76561198060874546#!/compare/1567123200/1567209600

Keys

Sale 14:

https://backpack.tf/profiles/76561198217906212#!/compare/1564876800/1564963200

https://backpack.tf/profiles/76561198131983415#!/compare/1564876800/1564963200

Sold for Keys

Sale 15:

https://backpack.tf/profiles/76561198131983415#!/compare/1564963200/1565049600

https://backpack.tf/profiles/76561198156255538#!/compare/1564963200/1565049600

Sold for ~15 keys

Sale 16:

https://backpack.tf/profiles/76561198156255538#!/compare/1566259200/1566345600

https://backpack.tf/profiles/76561198036270946#!/compare/1566172800/1566345600

Bulk

Sale 17:

https://backpack.tf/profiles/76561198046727007#!/compare/1538092800/1561593600

https://backpack.tf/profiles/76561198114402400#!/compare/1561507200/1561593600

Untrace

Sale 18:

https://backpack.tf/profiles/76561198114402400#!/compare/1562284800/1562371200

https://backpack.tf/profiles/76561198884025835#!/compare/1561939200/1563148800

Sold for Smoking Bomber + ~7 keys in sweets

use there

Sale 19:

https://backpack.tf/profiles/76561198380849939#!/compare/1563753600/1564272000

https://backpack.tf/profiles/76561198445063510#!/compare/1564099200/1565136000

Untrace

Sale 20:

https://backpack.tf/profiles/76561198445063510#!/compare/1564099200/1565136000

https://backpack.tf/profiles/76561198314349856#!/compare/1565136000/1565222400

Sold with negligible sweets for 20 keys

Sale 21:

https://backpack.tf/profiles/76561198314349856#!/compare/1565136000/1565222400

https://backpack.tf/profiles/76561198079504588#!/compare/1565136000/1565222400

Untrace

Sale 22:

https://backpack.tf/profiles/76561198079504588#!/compare/1565222400/1565308800

https://backpack.tf/profiles/76561198129995083#!/compare/1565222400/1565308800

Bulk

Sale 23:

https://backpack.tf/profiles/76561198129995083#!/compare/1565308800/1565395200

https://backpack.tf/profiles/76561198002757046#!/compare/1565308800/1565395200

QS

Sale 24:

https://backpack.tf/profiles/76561198002757046#!/compare/1567123200/1567209600

https://backpack.tf/profiles/76561198315568451#!/compare/1554336000/1567468800

Sold for Isotope Polar MW Mackerel + 2 keys

use there

Total sales @:

15, 18, 20, 22, 22, 22, 25 keys

Buyers up to 14 keys,

calling 15, 18 low, 25 high,

Taking 20 - 22 keys

K1ng's Part:

18 went via buy order:

https://bot.tf/stats/listings/MXQE789D

Unless there are other traceable sales at 18, I believe 20-25 (or even 20-22 if you want to even out the range, your choice) should be better here.