Suggestion: Frozen Icefall Bomb Beanie at 145 keys

Basically you have to figure out a suitable value for the unusual it was traded for (the football helmet). Determining this value (by looking at sales for that item) is called a mini.

Currently there is a misty skull football helmet for sale at 200 keys

helmet bought for 136 https://backpack.tf/profiles/76561198059323294#!/compare/1627603200/1628380800

you can resuggest this at 136 since that's what you paid

The Helmet has more sales: sold for ~94 keys here

https://backpack.tf/profiles/76561198157176919#!/compare/1627171200/1627776000

https://backpack.tf/profiles/76561198255764866#!/compare/1628294400/1628380800

https://backpack.tf/profiles/76561198070664972#!/compare/1627689600/1627776000 ----- 22 keys were used for the Beenie

https://backpack.tf/profiles/76561198354924601#!/compare/1627689600/1627776000 ----- ~30 keys for the Max's Head

Sold for 99 keys here:

https://backpack.tf/profiles/76561199125443371#!/compare/1627171200/1627257600

https://backpack.tf/profiles/76561198376445034#!/compare/1627084800/1627171200

So the Helmet can be suggested at 94-136 and the Bomb Beanie at 115.

Where’s the bomb beanie being sold for 115?

The Bomb Beanie sold for the Helmet, which is valued at 94-136. The median is 115 and that's the value that should be taken for the Beanie.