Ultimately what we all are looking for is Page Popularity for specific key phrases. The relationship between high pagerank and page popularity is uncertain, what is certain is anchor text of the sites linking to you is what gives your key phases higher "page popularity".
Buying text links from high ranked, authority web sites will speed the process, but having a boat-load of targeted links from 100 to 200 sites for each key phrase is just as important to your success.

Develope a Page Popularity Strategy

• Decide what your most important key phrases are and make a list ranking them from one to ten. You don't always want the most competitive key phrases. Many times you can get more traffic from a less competitive key phrase rather then a "blockbuster" key phrase with much more competition.
• Pick four or five of the key phrases you think will work best for your site.
• Buy links on 2 or 3 high PR sites for each of your major key phrases. Make sure the links you buy are in your site's general category. Not only will this boost page popularity, you'll get some traffic from the site.
• Then for each of those key phrases look for cheap deals on 20 low PR sites. Stop by LinkAdage™ on the weekend and shop for bargains. Most of the big buyers are Monday thru Friday type guys, so the weekends are when bargains can be found.
• Once your own PR increases as a result of these links, you will get more reciprocal link offers then you can handle. Pick and choose the best offers and make sure you request that your link trading partner uses one of your key phrases. Most importantly, make sure the link adds value to your site.
• Each of your key phrases should have between 100 and 200 links pointing your site. Some one-way high PR links, some some one way low PR sites, and a bunch of free reciprocal links is the recipee for success.

The key is to choose your key phrases carefully. The last thing you want to do is waste time and money on links with the wrong key phrase anchor text. Use some of the key word finder tools out there to assist with this task.
With the above strategy, it is quite possible to achieve top 10 rankings for your top "key phrases". If you accomplish this, depending on what you are selling, the sky is the limit.