Really? Assuming a two-person mirror, if you get 20*Silver, 4*Feodum that's 4*6=24 points. If you trash those 24 cards, and the extra 12 Silvers that trashing the Feodums gives you, that's 36 points. So you have to work very hard ideed for a Feodum to be worth more to you in your deck than as trash.
Having made that observation, if you only get 4VP by trashing Feodum and the three Silvers it gives, and Feodum costs $4, maybe it's easier just to get four more Silvers with your Masterpiece?
So I'm tempted by Market Square, Donate, Masterpiece. What am I overlooking?