You might want to check out
http://www.linkworth.com/ to discover the so called 'values' of a text link where it concerns
PR. Be careful about transacting anything there, though. I have not had good experiences over all with their platform (especially getting paid) when I was experimenting there a year or so ago. I closed out our account.
I would just use that site for due diligence and as a study aid.
Hope that helps!
Lilly