backlinks from main pages?

So some of my competition has heap loads of backlinks from blogs under "check out our these sites also/check out our friends/etc" on the main page.

So.. im guessing they are purchased? Anyone now a similar service that I can throw some money into that would put give me backlinks on main pages of sites.

Maybe a blog network?

Any advice is appreciated.

They probably own the sites or bought the links. There are link brokers out there, just search for them. They are pretty pricey though, so you're better off buying them yourself from individual webmasters.