Where are you buying Backlinks
 

Where are you buying quality backlinks

Where are you pointing your backlinks?

If you are worried about the quality of the link, then point it to a page within your domain... sub.domain.com or domain.com/subfolder/ ... instead of only linking to your index page.

That is a good way to boost your Domain Authority.

Ray
Hardlinks.org

I know a place or two ;)

Try the Buy and Sell section here