Sale 1: ~14 Keys Pure.

https://backpack.tf/profiles/76561198154700747#!/compare/1551225600/1551312000

https://backpack.tf/profiles/76561198084184648#!/compare/1551225600/1551398400

Sale 2: ~10 Keys Pure.

https://backpack.tf/profiles/76561198084184648#!/compare/1555459200/1555718400

https://backpack.tf/profiles/76561198171107913#!/compare/1555372800/1555459200

Sale 3: Use There.

Sold for Disco Beat Down Ol' Snaggletooth.

https://backpack.tf/profiles/76561198212497608#!/compare/1555718400/1555804800

https://backpack.tf/profiles/76561198083640007#!/compare/1555718400/1555804800

Sale 4: ~13 Keys.

https://backpack.tf/profiles/76561198083640007#!/compare/1555804800/1555891200

Sale 5: ~11 Keys.

Sold With 1 Key For Cloud 9 Bombing Run (11.5). (11.5-1=10.5)

https://backpack.tf/suggestion/5cd305bbd3817207fb20e0c8

https://backpack.tf/profiles/76561198145535039#!/compare/1555804800/1555891200

https://backpack.tf/profiles/76561198047819527#!/compare/1555804800/1555891200

Sale 6: ~12 Keys Pure.

https://backpack.tf/profiles/76561198047819527#!/compare/1555977600/1556064000

https://backpack.tf/profiles/76561198154700747#!/compare/1555977600/1556064000

Sale 7: Use There.

Sold with 2 keys for Strange Steaming Crack Pot

https://backpack.tf/profiles/76561198154700747#!/compare/1556841600/1556928000

https://backpack.tf/profiles/76561198024590544#!/compare/1556409600/1556841600

Sale 8: ~12 Keys Pure.

https://backpack.tf/profiles/76561198021272428#!/compare/1555891200/1556064000

Sale 9: ~10 Keys Pure.

https://backpack.tf/profiles/76561198073269221#!/compare/1551484800/1551571200

https://backpack.tf/profiles/76561198219288407#!/compare/1551484800/1551571200

Sale 10: ~10 Keys Pure.

https://backpack.tf/profiles/76561198219288407#!/compare/1552694400/1552780800

https://backpack.tf/profiles/76561198251370744#!/compare/1552694400/1552867200

Marketplae.tf Sales:

https://marketplace.tf/items/31008;5;u121

Sale 11: ~14 Keys.

Mar 8

$25.99 / $1.8 = 14.44 keys

Sale 12: High.

Mar 24

$49.38 / $1.8 = 27.43 keys

Including Sales: 10/10/10/11/12/12/13/14/14

Going with 10-14 keys.

Thanks to scourge for the premium!