First Suggestion :D

This hat sold consistently at around 36-38 keys in items, although there were one or two outliers at higher prices.

Evidence:

https://backpack.tf/profiles/76561198058857487#!/compare/1415692800/1415779200

Sold with about 5 keys for a Terror Watt Tyrant's Helm (36)

https://backpack.tf/profiles/76561198069677815#!/compare/1416038400/1416124800

Sold for a Disco Beat Down Large Luchadore (36)

https://backpack.tf/profiles/76561198069677815#!/compare/1416038400/1416124800

Sold for an Aces High Galvanized Gibus (39 at the time, I would know as I was the owner)

If you can think of ways I could improve, let me know in the comments for next time. Thanks!