In an interview with Stephan Spencer, Matt Cutts, the Google Spaminator admits that aggressive link buying is “more likely to help” than harm a website. Look for the quote a bit over half-way down the interview.
This may be just stating the obvious, because anyone who is still buying links will be able to produce the evidence for themselves and not need affirmation from Matt Cutts, but I think it’s an interesting point to make after such a turbulent few months in the SEO industry.
Personally, I think if you’re in a competitive industry, you have to buy links. If you don’t, you won’t compete. That goes double so for newer websites, and websites without massive marketing budgets.
Knowing where to buy your links is now the real test.