You can let your opponent get the first three Feoda and only lose the split 3/5; if you bought more (and bigger) Masterpieces, you still easily have more points, and are in a better position to buy Provinces too. A Margrave looks like a good addition at some point, I'll concede that, but on pretty much any Masterpiece/Feodum board, it's hard to find anything that snowballs faster than just buying bigger Masterpieces with the Silver you got from the previous ones. If I just drop two Coppers to the discard attack, I get two fewer Silvers that turn, but you already sacrificed at least two Silvers one shuffle earlier by buying the Margrave, so it may be ignorable anyway.
For Trader/Feodum, the Feodum split matters - you never need to buy anything for more than $4. For Masterpiece/Feodum, the Silver split is more important - more Silvers now means more Silvers next shuffle, in an exponential feedback loop.