Resuggestion, thanks to Cashew for the info!

Sale 1:

https://backpack.tf/profiles/76561198211694452#!/compare/1550188800/1550275200

https://backpack.tf/profiles/76561198073438708#!/compare/1550188800/1550275200

Keys, QS?

Sale 2:

https://backpack.tf/profiles/76561198073438708#!/compare/1552780800/1552867200

https://backpack.tf/profiles/76561198053547683#!/compare/1552694400/1552867200

Sold with 18 keys for GE Fedora

Use there

Sale 3:

https://backpack.tf/profiles/76561198053547683#!/compare/1552867200/1552953600

https://backpack.tf/profiles/76561198173073890#!/compare/1552867200/1552953600

Sold with 26 keys in sweets for GE Lucky(63)

Total is 37 keys

Sale 4:

https://backpack.tf/profiles/76561198173073890#!/compare/1553385600/1553472000

https://backpack.tf/profiles/76561198121991829#!/compare/1553385600/1553472000

Sold for Ch Guad + 5 keys

Guad Mini:

https://backpack.tf/suggestion/5cde9d68d38172272c5a9ef0

Suggestion for 28 keys

Total is 33 keys

Sale 5:

https://marketplace.tf/items/247;5;u10

$67.79 / $1.75 = 38.74 keys

Total sales @:

35, 37, 38.74 keys

Cashew's Part:

https://backpack.tf/profiles/76561198267189538#!/compare/1554681600/1554768000 sale at 33

ch guad sale will also be slightly lower. Could give this a larger range

Taking 33 - 39 keys