In reality, I think it will create 2 distinct tiers for their records. The popular, high demand titles (the De La Souls of the world for example) will likely increase in value, but the less popular picks will plummet and likely flood the market (idea being that subscribers will want to recoup some of their loss no matter what and are less likely to keep a mediocre 40 dollar record).
VMPs success will entirely depend on having the former outnumber the latter in a way that they don't lose subscribers due to content. They seem perfectly happy to lose subscribers for monetary reasons.