Sale 1:

https://backpack.tf/profiles/76561198105484257#!/compare/1531958400/1532044800 Bulk for Miami Nights Nunhood

https://backpack.tf/profiles/76561198041902665#!/compare/1531958400/1532044800 Moonman sold it later to scrap, so not using that either

Sale 2:

https://backpack.tf/profiles/76561197999751332#!/compare/1531872000/1532390400 1:1 with a Purple Confetti Letch's LED?

Open suggestion at 12-15= 13.5 keys

Sale 3:

https://backpack.tf/profiles/76561197999751332#!/compare/1532390400/1532649600 1:1 Subatomic Universal Translator

= 18 keys

Sale 4:

https://backpack.tf/profiles/76561197995355045#!/compare/1532736000/1532908800 then it was traded back 1:1 for the Subatomic Translator

= 18 keys

Sale 5:

https://backpack.tf/profiles/76561197999751332#!/compare/1532908800/1532995200 1:1 for Green Confetti Tundra Top

= 17.5 keys

We have sales at 13.5 keys , 18 keys, 18 keys and 17.5 keys, rounding 17.5 keys to 18 to make it nicer.

Excluding 13.5 keys sale, since it is an outlier