You can search for some one selling PR3+ backling on this forum, just type it in and you get lots of results...
Try to do Press releases. A link from big news papers etc will help you a lot in your serp rankings. We ranked one of our client with few Press release which got viral and got us around 30 odd top notch back-links. Such links are really hard to get but really pretty effective.
Just one? Buy it... try the buy sell trade section of this site for Link Sellers. Press releases aren't a bad idea either, just don't over-optimize anchors http://searchengineland.com/google-adds-large-scale-guest-posting-advertorials-optimized-anchor-text-to-list-of-link-schemes-168082
I would definitely consider buying some. The secret is to get high quality, relevant and permanent links. One solid, relative link is worth a million cheap spammy ones. You might consider searching on Fiverr.com, or even contacting blog owners one by one. (I've had people email me and offer me $50 - $80 for a backlink, maybe you could follow suit?) To find some blogs that might be interested just check technorati. Or, if you want to spend less, use Fiverr. Remember though; quality over quantity. Just my $.02
put your keyword(s) related to your web page in Google search box, select "discussions" or "blogs" and try to put your site link there varying your anchor text.. it would help a lot.
Can we get strong backlinks by doing direcctory submissions, social bookmarkings and forum marketing process?