Running a Carfax or equivalent on any specific VX's in your area would help you determine a past history of each one, and once you have the last four digits of the VIN#'s, you could then run a similar search here to research past ownership and get a better idea of the diligence the owner(s) had for maintaining each VX.

VX market price/value is a tricky subject. About the most consistent advice you'll find from VX owners here is to buy low and sell high.