Is buying links worth it?

In your opinion, is buying individual links on high PR sites worth it? Or is it better to stick to blackhat methods to get backlinks.

Yes. The answer is Yes.

why is it good to buy backlinks?

When buying backlinks, always request the OBL and if it is sitewide.. If there are either of these it is an automatic alert to Goog and might take a closer look.. Sitewide links can be dangerous these days, so just be cautious. If I were you I would probably stick to High PR blog posts that only keep around 10-20 posts on homepage. Remember if you backlink properly to these posts you can increase the deep PR pretty quickly.. I have actually gotten one the posts ranked for one of my long tail keywords and the PR on that URL is now a 3 (domain is 5), and the traffic is pretty good on there. Also try to submit your own spun article, it seems to be more legible.