Resuggestion, thanks to Blaze for the info!

Sale 1:

https://backpack.tf/profiles/76561198040965000#!/compare/1546819200/1546992000

https://backpack.tf/profiles/76561198060666689#!/compare/1510272000/1550188800

Untrace

Sale 2:

https://backpack.tf/profiles/76561198065179630#!/compare/1548201600/1548374400

https://backpack.tf/profiles/76561198049425694#!/compare/1548028800/1548892800

Sold for 22 keys

Sale 3:

https://backpack.tf/profiles/76561198305824514#!/compare/1546732800/1546819200

https://backpack.tf/profiles/76561198159656266#!/compare/1546732800/1546819200

Sold for Whirlwind Mannrobics + ~4 keys in sweets

Nothing usable on it

Sale 4:

https://backpack.tf/profiles/76561198159656266#!/compare/1547164800/1547251200

https://backpack.tf/profiles/76561198409848535#!/compare/1548806400/1548979200

Untrace

Sale 5:

https://backpack.tf/profiles/76561198409848535#!/compare/1548806400/1548979200

QS to bot

Sale 6:

https://backpack.tf/profiles/76561198160856661#!/compare/1549152000/1549238400

https://backpack.tf/profiles/76561198072355915#!/compare/1549065600/1549152000

Bulk

Sale 7:

https://backpack.tf/profiles/76561198179502089#!/compare/1549843200/1549929600

https://backpack.tf/profiles/76561198072355915#!/compare/1549756800/1549929600

Sold for KaW Dogger + ~4 keys

Dogger Mini:

https://backpack.tf/suggestion/5c70f14ad381722ade22a9d7

Suggestion for 16.5 keys

Total is 20.5 keys

Sale 8:

https://marketplace.tf/items/139;5;u33

$49.99 / $1.64 = 30.48 keys

Blaze's Part:

sale 8 had a b/o of 24: https://imgur.com/a/1h5b13S

Taking 21 - 24 keys