Ehh, it would depend upon the price point of the VP card. For instance, if the VP card cost 5 or less, then it will be far better to treat this as a gardens/goons type game where maximizing +buy is better than maximizing cash value. So opening something like hamlet/market would be far better than haven/mountebank. Certainly you'd almost always buy coppers with spare buys.
This would, of course, finally make talisman massively effective, which is almost always terrible in BM type games.