Why would you buy links when you could just setup a link farm?
50 or 60 domains all hosted on a cheap shared hosting account running some lame PHP link farm script from a few years ago should do well. Just make sure the domain reggie doesn't point back at you.
You only buy links so that it appears like you've got an organic link farm instead of a mass produced one. Remember only Google is allowed to sell links, cuz they put them in a slightly yellow box or something. If other people could get you to the front page of google it would undermine Google's business model.
See also: "If I change my name to Mark Zuckerberg, they can't sue me, because the judge will think I'm Mark Zuckerberg!"