There was a bloke doing some building work where I work. Ended up chatting to him as we boh smoked, and it turned out he also had a metal detecting shop and did it as a hobby (and yes he had a beard)
Turns out people were always coming into his shop offering him gold and silver finds worth thousands, but it's all kept quiet because of "treasure trove" rules.
So I'd suggest developing an encyclopedic knowledge of metal detectors, open a shop, and cash in on dug up booty from the nerds on the cheap.