without providing an alternative strategy
It's great for 3-piling, since you can gain them all with a single buy and the ones after the first are cheap. It definitely changes the game, much more than Feodum in most kingdoms, I would say.
You need $18 to buy them all, a figure that's quite hard to reach.
You might as well get to $16 with 8 buys and clear out the Estates, which you can do already.
Now I agree that Feodum is often weak, but that's Feodum's problems. At least it attempted to make a certain strategy viable.
Note that there are no vanilla VP kingdom cards currently in existence. They either give VPs for something (actions, silvers, differently named cards) or provide something along those VPs (a reaction, action or treasure).
And this design is about as close as you can come to a vanilla VP card without it being strictly vanilla.
I think it would be better to either have:
- a regular card for which you can overpay for VPs
- a VP card which provides something other than VPs if you overpay for it
If you're going with the second idea, you can have something like:
Windmill
Victory - $3+2 VP
When you buy this, you may overpay for it. For each $ you overpaid, reveal cards from your deck until you reveal a Victory card. Discard all revealed cards.
Now, whether or not this is a strong overpay effect doesn't concern me, only the fact that a VP card with overpay for something else might work.