I'm trying to get some backlinks to a new site, but I'm somewhat new to the link buying business. Assuming I could buy 6 PR5 links for the price of a single PR 7 link, which would be better? In addition, is a PR6 link an ok substitute for a PR 7 link? I'm on a budget and can get a PR 6 link free on one of my own sites and don't want to cough up for a pricey PR7 link unless it's absolutely necessary.
I would go with both Its 50-50 I would advise you to buy 50 PR5 links rather than 10 PR7 links as 50 PR 5 links would get you links from more websites in number than PR7 websites
A PR7 link is worth close to a 100 PR5 links. Get that. Or 4 PR6 links. But, make sure they are all relevant, have a lot of backlinks and have legiimate PRs. PM me for clarifications.
It gets very confusing but the best thing to do in my opinion is to buy as many high pr's as you can afford and aim at an even balance.
There are arguments for and again whatever permutation of links you buy, I will suggest a combination of P7 and as many PR 5 or 6 more links you can buy.