The PMC is one of the most valuable Steve Vai Ibanez models, but 70%-80% condition doesn't sound very good. Is the damage in the finish/body and neck, or is it hardware? If all it needs is a new trem, knobs, pickups, etc. it'd probably be worth it for you to replace the parts before you sell it. But if the finish is damaged, you'll have to lower your expectations.
I don't really have a good idea what less-well-preserved swirls go for, but I know that mint ones sell from $1500 or $1750 on up (sometime, way up!). Definitely tell the group exactly what is wrong with the guitar -- then, people around here who are smarter and more experienced than I can give you a better estimate. In any case, it's an awesome guitar. Best of luck!