Sale 1:

https://backpack.tf/profiles/76561198080179568#!/compare/1541462400/1541548800

https://backpack.tf/profiles/76561198027338258#!/compare/1541548800/1541635200

Sold for 28 keys

Sale 2:

https://backpack.tf/profiles/76561198027338258#!/compare/1542758400/1542844800

https://backpack.tf/profiles/76561198040280241#!/compare/1542758400/1542844800

Bulk

Sale 3:

https://backpack.tf/profiles/76561198043716833#!/compare/1547078400/1547164800

https://backpack.tf/profiles/76561198043566764#!/compare/1547078400/1547164800

Bulk

Sale 4:

https://backpack.tf/profiles/76561198159152968#!/compare/1545523200/1545609600

https://backpack.tf/profiles/76561198045783975#!/compare/1545523200/1545609600

Sold for 38 keys

Sale 5:

https://backpack.tf/profiles/76561198045783975#!/compare/1547078400/1547164800

https://backpack.tf/profiles/76561198122321044#!/compare/1547078400/1547164800

Sold for Beams Blast Defense

Blast Mini:

https://backpack.tf/suggestion/5c49482444325a74a03a1bf6

Suggestion for 45.5 keys

Sale 6:

https://backpack.tf/profiles/76561198114764948#!/compare/1543968000/1544140800

https://backpack.tf/profiles/76561198027338258#!/compare/1544054400/1544140800

Sold for 34 keys

Sale 7:

https://backpack.tf/profiles/76561198136866711#!/compare/1541548800/1541808000

https://backpack.tf/profiles/76561198153789411#!/compare/1541635200/1541808000

Sold for GE Blast Defense + ~1 key in sweets

Blast Mini:

https://backpack.tf/suggestion/5c4ab37044325a10b4067161

Suggestion for 36.5 keys

Total is 37.5 keys

Sale 8:

https://backpack.tf/profiles/76561198153789411#!/compare/1542067200/1542240000

https://backpack.tf/profiles/76561198094281531#!/compare/1542067200/1542326400

Sold for Aussie Sticky(26)

Sale 9:

https://backpack.tf/profiles/76561198002757046#!/compare/1540857600/1540944000'

https://backpack.tf/profiles/76561197960958019#!/compare/1540857600/1540944000

Sold for 28 keys

Sale 10:

https://backpack.tf/profiles/76561197960958019#!/compare/1540857600/1540944000

https://backpack.tf/profiles/76561198079275897#!/compare/1539043200/1540944000

Bulk

Sale 11, 12:

https://marketplace.tf/items/30863;5;u10

Sold for 80, 95 USD

Keys at 1.77, 1.75 USD

Total is 45.20, 54.29 keys

Total sales @:

26, 28, 28, 34, 37.5, 38, 45.20, 45.5, 54.29 keys

Buyers up to 28 keys,

Seller at 40 keys,

Let's go with 34 - 38 keys.