This is a pretty neat idea! This specific version it too weak, though. Being a cantrip is a huge advantage over Salvager but it's far, far less flexible. And since it only gives $1 more than Gold would have, it essentially is a market if and only if you trash a gold from your hand. That's too harsh. I'd actually mess around with giving it +$6, because that makes it stronger than a grand market but only if you trash gold. Or if you don't mind sacrificing the theme some, you could give it a bonus for trashing actions too. Maybe:
You may trash a card from your hand.
If it is a Gold, +1 Card; +1 Action; +1 Buy; and +$5.
If it is an Action card, +3 Cards and +1 Action.
That buffs this card a bit and makes it like a mini-apprentice. And it lets you trash coppers curses, and estates, but for no benefit. This version might be way too strong with Ruins.
Edit: Added +buy to the proposed card to make it truer to the original. Also grammar.