In this morning's paper a story about a guy that found two cases of hard hats by a dumpster. Turns out they were Bullard Hard Boiled 502's, very collectible because they were standard issue at a lot of big jobs, like the Golden Gate Bridge.
He has made $15000 on EBay so far. One sold for $475.
When I went to Intel for the build out in the early 90's I was issued a Bullard 502. As I considered it my lucky hat it's all I've worn. Now I see even ones with a history, like company stickers or job sites om them also go for big bucks.

I'll keep it though even it looks like it's been dragged behind a truck.