This is more a general comment open to discussion rather than a specific question. But what I find really incredible is that people will buy links just because a site has high PR. That is not even a wise business decision. The idea of promoting a website is to get traffic and earn revenue from that traffic. Many of these supposed high pr sites do not have traffic to even help. I would much rather buy on a PR 0 site with legitimate documented traffic that will go to my site that something with a high PR that means nothing in terms of me making a living.
I agree. I've noticed a lot sites like you described as well. A lot of them just go out and pay the high pr sites for that linking but don't do anything after they get it. I think if your page has a pr of 1 then you should only be trying to link to pages that have a pr of 2. THen once you get to 2 then start trying to link to pages that have a 3. It's a gradual progression but you'll get there eventually.