This is the hat you think it is.

Sale 1.

https://backpack.tf/profiles/76561198029895408#!/compare/1620432000/1620518400

https://backpack.tf/profiles/76561198155699667#!/compare/1620345600/1620518400

Sold to Burning Flames Das Hazmattenhatten with Strange Disco Beat Down Killer Exclusive. Better to use it there.

Sale 2.

https://backpack.tf/profiles/76561198155699667#!/compare/1621209600/1621382400

https://backpack.tf/profiles/76561198029895408#!/compare/1621296000/1621382400

I don't use this because it looks like a quicksell.

Sale 3.

https://backpack.tf/profiles/76561198029895408#!/compare/1622419200/1622505600

https://backpack.tf/profiles/76561197966563795#!/compare/1622419200/1622505600

Sold for 460 keys with Sunbeams Flash of Inspiration. Since Flash of Inspiration's suggestion is at 200, the plumber is judged to be 260.

260

(If I can use Sale 1 here, please tell me.)