It all depends on a huge variety of factors. What's important is the increase in SERP's you gain from the backlinks, if any. If they jump your page to a PR4, and your SERP's don't increase, then the links aren't worth much to you.
Yeah, I could care less about my pr, i'm talking serp boost. With that said I've already seen a boost from them, my main keyword in Google went from page 24 to page 12 in the last 4 days and still climbing it seems. We were already towards the top of page 1 in msn and yahoo, just needed a little extra boost to get Google to start ranking us better.