Sorry if this seems a stupid post but I'm astonished... I see plenty of people on those forums selling or buying link pretending to know a lot about seo... and then they don't know a simple principle: doesn't matter only the PR. It matters also HOW MANY LINKS are in the page!!!!!!!!! Use always tools like this one: http://www.urltrends.com it gives you a good estimate on how much PR each outbound links gets. In any case I would stay away from buying those 200 blog links offer, and save money to buy 1 link for $20-30 but that will have some impact on your SEO (because the others will have none).
LoL. It's one of the basic rules... I have one more advice for you: Links in the main content (in the text) are better than links in the footer.
rei1974, this is a simple principle, but indeed very few people know that - I offer a link on a Google indexed page (currently with PR0) and a guy with 40 links on his PR3 resource page would not give me a 41th, just because I have no PR. Being 3rd, his link would benefit a way more than mine on the 41th place...
As you can see, what is obvious for me (and many other good SEO) is not so obvious for some other people. And judging on link sales how much success have those offer "your link on 150000 blog post" - they don't understand that those blogs are going to be dropped or blacklisted from google because they'll have all the same content??
Before I purchase a link, I always look at the number of links on the page and I check out the sites that they are linking to