Resuggestion, thanks to K1ng for the info!

Sale 1:

https://backpack.tf/profiles/76561198337734785#!/compare/1534896000/1534982400

QS

Sale 2:

https://backpack.tf/profiles/76561198337734785#!/compare/1535241600/1535328000

https://backpack.tf/profiles/76561197999873164#!/compare/1535328000/1535414400

Sold for keys, untrace.

Sale 3:

https://backpack.tf/profiles/76561198281956556#!/compare/1531353600/1531440000

https://backpack.tf/profiles/76561198316961222#!/compare/1531267200/1531353600

Keys (QS?)

Sale 4:

https://backpack.tf/profiles/76561198254491860#!/compare/1531353600/1531440000

https://backpack.tf/profiles/76561198376331369#!/compare/1531353600/1531440000

Sold for 18 keys + negligible sweets

Sale 5:

https://backpack.tf/profiles/76561198376331369#!/compare/1531612800/1531699200

https://backpack.tf/profiles/76561198132246961#!/compare/1531612800/1531699200

Sold with 2 keys for PE Sinner Shade + negligible sweets

Use there.

Sale 6:

https://backpack.tf/profiles/76561198132246961#!/compare/1531699200/1531872000

https://backpack.tf/profiles/76561198140565712#!/compare/1531785600/1531872000

Sold for 16 keys

Sale 7:

https://backpack.tf/profiles/76561198140565712#!/compare/1531785600/1531872000

https://backpack.tf/profiles/76561198397970914#!/compare/1531785600/1531872000

Sold for 19 keys

Sale 8:

https://backpack.tf/profiles/76561198397970914#!/compare/1531872000/1531958400

https://backpack.tf/profiles/76561198027857565#!/compare/1531872000/1531958400

Sold for CH HTKF

Use there.

Sale 9:

https://backpack.tf/profiles/76561198027857565#!/compare/1531872000/1531958400

https://backpack.tf/profiles/76561198169855930#!/compare/1531872000/1531958400

Sold with 3 keys for CPS Kabuto

Kabuto Mini:

https://backpack.tf/suggestion/5b87f3dd44325a566317ecb7

Suggestion for 23 keys

Total is 20 keys

Sale 10:

https://backpack.tf/profiles/76561198169855930#!/compare/1533168000/1533600000

https://backpack.tf/profiles/76561198334598690#!/compare/1533513600/1533600000

QS?

Sale 11:

https://backpack.tf/profiles/76561198334598690#!/compare/1534291200/1534377600

https://backpack.tf/profiles/76561198354544795#!/compare/1534032000/1534464000

Sold for 24 keys

Total sales @:

16, 18, 19, 20, 24 keys

K1ng's Part:

Well, there are too many low outliers. The Heart HTKF would support 20 if used here:

https://backpack.tf/suggestion/5b88207244325a6ad07fd30a

The sales at 18 and 19 went quick, so 20-24 should be okay.