I didn't see anyone on this forum selling really good quality backlinks (maybe I didn't look good enough?).
The main thing that sellers push is the amount of backlinks....
Many of backlink buyers just waste their money and moreover, they pay for what probably hurt them more than help...
Don't be stupid, don't buy backlinks without real understanding what exactly you are getting. You shouldn't make accent on the number of backlinks, but on their quality. You only need one or a few good backlinks than 1k of crap.
Read this to understand which backlinks are good and worth your money:
What is a ?Good Quality? Backlink?