Theres not really any way to know for sure because of the amount of variables. Page rank alone is not a good measure of the value of a link because it changes all the time. Traffic is a good measure and you want traffic related to your site. theres no solid way costing a link
ok, i guess you want something like that to use it as a link buying or exchange criteria if that's the case, you can easily code your own algo some of the main factors would be : 1. Page Relevance to your niche ? 2. Your keywords in the link page URL ? 3. Number of back links the page has 4. Number of external links on the page where your link will appear 5. Age of the domain 6. Page Rank of the Page use those factors inside a few lines of code (php or even a desktop application) and you got yourself your own ranking algo if you don't code, outsource it! good luck
Build free links to start off with, then, when you are actually making money online, begin to research some paid linking techniques, start from the bottom to get to the top...
Can anybody provide a formula or some algo to calculate the price base on the following: Google PR Alexa Number of Yahoo/Google backlinks Number of external links on the page