New LPs are very hit-and-miss. It is basically a selection between two radically differing qualities; on the one hand, there are the far and few plants that press high quality LPs with great attention to detail, and on the other, there are the majority of plants that press flimsy, dirty, scratched, dry pieces of garbage.
The majority of the former plants charge huge premiums for their records. Unless the new LP has a significantly better mix than the original pressing, it is probably a safe bet to go with the original pressing. If it's a new album pressed onto vinyl, it most likely isn't worth buying because the recording equipment used has already taken the virginity of the recording. Unless you're a badass like Neil Young and record everything on analog tape still. Then the new LP is worth it.
The bottom line is, unless it's pressed by Mobile Fidelity, or RTI in accordance with Steve Hoffman, it probably isn't worth buying. And, with the astronomical prices these products go for, they often aren't even worth it then unless for the ultra-OCD music collectors.