Sale 1: 16 keys pure; took 2 months to sell so no QS

http://backpack.tf/profiles/76561198002757046#!/compare/1489363200/1489449600

http://backpack.tf/profiles/76561198215879363#!/compare/1488412800/1489449600

Sale 2: Sold for Miami Nights Conquistador (17.5; in-date) + 1 key --> 18.5; rounding to 19 keys.

http://backpack.tf/profiles/76561198213807465#!/compare/1492214400/1492300800

Sale 3: 17 keys on marketplace (thanks to sin for helping me here) --> 17 keys

https://marketplace.tf/items/377;5;u33

Sale 4: Sold for Strange Professional Killstreak Australium Tomislav (15.5) + Strange Festive Sandvich (3.5) + Strange Specialized Killstreak Bread Bite (1.5 keys) + sweets (~ 30 ref)

B/O was 20 keys --> 20 keys

http://backpack.tf/profiles/76561198296290397#!/compare/1493769600/1493856000

Sale 5: Sold for Cloud 9 Gym Rat

http://backpack.tf/profiles/76561197989774972#!/compare/1493424000/1493769600

This sale can be used to update the outdated Gym Rat.

Sale 6: Sold for Starstorm Insomnia Nasty Norsemann (21 keys; mini below; B/O was 16 keys) --> 16 keys (credits to Jarool for finding the b/o)

http://backpack.tf/profiles/76561198273681900#!/compare/1492214400/1492300800

Mini Norseman: 21 keys pure

http://backpack.tf/profiles/76561198064682618#!/compare/1492387200/1492992000

Thanks to Zeus Junior for helping me out here!

--> Sales at 16, 16, 17, 19, 20

--> Suggesting range from 16-20