I don't really understand what you mean by 'with a single copper', but well, e.g.
TR-KC chain playing 20 KC'd possessions (using outpost)
Masquerade them the single copper.
TR-KC chain on each possession turn, playing 10 KC'd coppersmiths.
Total value attained from that copper before the opponent sees a turn:
20*3*31 = 1860
It seems difficult to define what's counted here. If on discard cards is allowed, then what about trash with benefit? With develop, mint and remodel/expand, you can concievably turn that single copper into every (non-potion cost) card in the game in a single turn.