Sale 1:

https://marketplace.tf/items/315;5;u32

$70.00 / $1.82 = 38.46 keys

Sale 2:

BP buy

https://backpack.tf/profiles/76561198117673174#!/compare/1551052800/1552176000

Sale 3:

untrace

https://backpack.tf/profiles/76561198158206236#!/compare/1552089600/1552176000

Sale 4:

untrace - histories dont match on anything

https://backpack.tf/profiles/76561198047092983#!/compare/1543795200/1552780800

https://backpack.tf/profiles/76561198158206236#!/compare/1552694400/1552780800

Sale 5:

untrace

https://backpack.tf/profiles/76561198064569267#!/compare/1549238400/1549497600

https://backpack.tf/profiles/76561198044278802#!/compare/1549497600/1549756800

Sale 6:

36 keys

Sold with 80 ref for Lantern Tossle Cap(38 keys)

https://backpack.tf/profiles/76561198044278802#!/compare/1549756800/1549929600

https://backpack.tf/profiles/76561198021055079#!/compare/1549843200/1549929600

Tossle:

38 pure

https://backpack.tf/profiles/76561198313538268#!/compare/1554336000/1554422400

https://backpack.tf/profiles/76561198106784075#!/compare/1553990400/1554422400

Sale 7:

45 pure

https://backpack.tf/profiles/76561198021055079#!/compare/1552953600/1553040000

https://backpack.tf/profiles/76561198084113284#!/compare/1552953600/1553040000

Sale 8:

use there

GBH Tam O' Shanter

https://backpack.tf/profiles/76561198084113284#!/compare/1553126400/1553212800

https://backpack.tf/profiles/76561198170190173#!/compare/1553126400/1553212800

Sale 9:

40 pure

https://backpack.tf/profiles/76561198170190173#!/compare/1553299200/1553385600

https://backpack.tf/profiles/76561198280975775#!/compare/1553299200/1553385600

Sale 10:

quicksell - sold in 3 days for less than bought it for

35 pure

https://backpack.tf/profiles/76561198128838220#!/compare/1553558400/1553644800

https://backpack.tf/profiles/76561198280975775#!/compare/1553558400/1553644800

Sale 11:

55 keys

Morning Glory Armored Authority(55 keys)

https://backpack.tf/profiles/76561198128838220#!/compare/1554336000/1554595200

https://backpack.tf/profiles/76561198850996337#!/compare/1554508800/1554595200

Armored Authority:

https://backpack.tf/suggestion/5c9e8308d38172192f5880f3

Sale 12:

using there

Starstorm Insomnia Heer's Helmet

https://backpack.tf/profiles/76561198062779400#!/compare/1547251200/1547337600

https://backpack.tf/profiles/76561198125791160#!/compare/1547251200/1547337600

Sale 13:

46 pure

https://backpack.tf/profiles/76561198125791160#!/compare/1547510400/1547596800

https://backpack.tf/profiles/76561198071520036#!/compare/1547510400/1547596800

Sale 14:

37 keys

Sold with 2 keys pure + 2 keys sweets for Planets Rack(41 keys)

https://backpack.tf/profiles/76561198071520036#!/compare/1550188800/1550275200

https://backpack.tf/profiles/76561198162277492#!/compare/1550188800/1550275200

Sale 15:

37 pure

https://backpack.tf/profiles/76561198162277492#!/compare/1550448000/1550534400

https://backpack.tf/profiles/76561198047941585#!/compare/1550448000/1550534400

Sale 16:

Bulk/using there

https://backpack.tf/profiles/76561198047941585#!/compare/1552348800/1552435200

https://backpack.tf/profiles/76561197971485686#!/compare/1552262400/1552435200

Sale 17:

Was used in that suggestion

Ooze Warming Wear

https://backpack.tf/profiles/76561197971485686#!/compare/1552953600/1553040000

https://backpack.tf/profiles/76561198064982470#!/compare/1552953600/1553040000

Sale 18:

37 pure

https://backpack.tf/profiles/76561198064982470#!/compare/1553040000/1553126400

https://backpack.tf/profiles/76561198055847835#!/compare/1552953600/1553212800

==============================================================================

Sales:

36,37,37,37,38,40,45,46,55

excluding 55 as high outlier