For SEO purposes the importance of your backlink's depends on how relevant they are to the content on your site.

If you have a blog about Gold watches and your backlinks are coming from every known place on the internet then there not doing you any good at all, profit wise.

100 pr6 targeted backlinks would be very costly. It depends where you getting from

100 quality PR6 backlinks from pages with a few external links would be $2,000 at least monthly. Its very less than the price but i just wanted to give you an estimation about the price of it. I suggest you to forget it because pagrank is not the only important factor for ranking pages. There are many other important factors too.

As SEO point of view "relevant" PR6 backlinks are better and prices as socialbookmark suggested.

My advise is not to buy a backlink. it is temporary. better hire seo expert and ask him to build the backlink. one way backlink is good. organic is good anytime

Why one should go for buying backlinks when one could easily promote a site for free. Well, what important is one should know how to promote a site properly, how to build good link popularity, submitting link or articles in good dofollow sites, etc.

I've got a question for the people above; who in bloody he!! is teaching you this nonsense?

OP, if you take any of this advice you'll get nowhere at all. What I've quoted is SO untrue it's not even tragically amusing.

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