Is there any rule of thumb that I can use to determine the monetary value of links from diferent websites based on their PR? i.e. how much aprox. is a link from a PR 9 website worth... or from a PR 7 website?
If you are asking if 2 PR9 sites will give you a PR7 site this question is unanswerable. Well you can get opinionated answers but every site works different along with the links. So i guess the answer is there is no rule of thumb unless someone made one up. Only rule of thumb is the higher the PR the more PR passed. I wouldnt focus on PR anyways unless you are making a site strictly for selling links.
I think you're talking about actual dollar figure for PR. I wouldn't base a text link on PR. Their needs to be other factors that compliment the PR value. Here are some other factors that should be consider for pricing: - Age of domain - Amount of backlinks to site/page - Number of pages indexed in big 3 (Google, Yahoo!, MSN) - PageRank - Amount of authority links If you have good amounts of all these variables, then the link would be worth some change.