31 keys doesn't sound too bad considering the hat is common and Uber Blaze is the 2nd most common effect on said hat.

There isn’t enough evidence; this hat has been sold multiple times, and the price of a single sale doesn’t set the standard. You should make a price suggestion based on as many sales as possible to establish a realistic price range.

https://i.imgur.com/HxeDg3b.png

https://backpack.tf/item/15045365278

https://backpack.tf/item/15015676694

https://backpack.tf/item/15006536549

- sellers at 27 - 30 keys