Though generally speaking, not more backlinks but more quality backlinks give good PR in Google-it is a good practice to get quality backlinks rather than getting lots of backlinks. It is said three links from PR7 websites is going to help you a lot more than 150 links from PR1 website. Well, why do a PR7 just link to you?

Maybe, start with a little bit quantity work will worth it. Because, you backlinks are directly proportional to your page rank, as whenever, Google updates the PR, it will distribute some amount of PR to the links lying on a page. If your link is lying on hundreds of web pages, then you might get some good PR still.

Cheers!