Sale 1:

Sold with ~45 in stuff for It's a mystery to everyone Duck Billed Hatypus (~200), 155 total

https://backpack.tf/profiles/76561198261521812#!/compare/1505174400/1505260800

Duck: Not outdated, but just sales that support current price

~200ish

https://backpack.tf/profiles/76561198179201573#!/compare/1504569600/1504656000

~200ish

https://backpack.tf/profiles/76561198179201573#!/compare/1503619200/1503705600

Sale 2:

Sold with Scorching Flames Airdog (~75) for Green Energy Slo-Poke (~200), 125 total. better use it for slo-poke

https://backpack.tf/profiles/76561198342438109#!/compare/1505088000/1505174400

Slo-poke:

~200

Ballcap is slightely outdated, but has no other sales

https://backpack.tf/profiles/76561198098367344#!/compare/1506124800/1506211200

Sale 3:

looks like quicksale, sold in a day

https://backpack.tf/profiles/76561198098367344#!/compare/1504656000/1504742400

Sale 4:

Sold for Frostbite Soldered Sensei (110)

https://backpack.tf/profiles/76561198123923889#!/compare/1504569600/1504656000

Sale 5:

Low

https://backpack.tf/profiles/76561198338958130#!/compare/1502064000/1502323200

Sale 6 and 7:

Qbought mine twice via my buy order

https://imgur.com/oFW0j5l

https://imgur.com/a/5RdVE

(cant provide my first purchase, it was exactly 1 month ago and i made no screens + guy spend all keys on unboxing so compare show nothin)

Sale 8: (credits to -GoV-Pixxi0us)

sold for blizz storm vive la france (80) + arround 18 keys in keys and sweets.

https://backpack.tf/profiles/76561198095862827#!/compare/1505174400/1505520000

Sales at 100,110,125(using here), 155 (outlier)

Going with 100-110 keys range