Is it better for pagerank to...

Is it better for my google pagerank to buy high pagerank links or to pay someone to submit my site to 500 directories?

 

It is not really the quantity of links, it's the quality, the sites that link to you and the percieved value of those links. I wouldn't get hung up on large backlinks numbers or high PR.

I'd go for option 3.
20 backlinks from related websites.

 

True words of wisdom

Also, make sure those bakclinks use anchor text containg the keyphrases you wish to rank well for.

 

Also it's worth remembering that Google Pagerank is not everything. PR does not equal search result ranking and does not equal high traffic or high sales/conversion rates.

 

I suggest to link exchange with keyword related websites by using a software like pr prowler. Hint - you don't have to pay for Page Rank

 

If you are after PR, just follow the good advice from Scott.

 

If it was a choice between the two for me I'd submit to the directories.

 

pr has very little to do with ranking. However a high pr means more backlinks. It is the relevancy of these links that are important....Are they from related websites ( eg do there share similar meta tags) and what is the anchor text used. Top keywords should be used in anchor text if you want to rank for these keywords.
Links from high pr sites are good, even better if they are related but make sure you pay the right price for these links. There are plenty of tools on the net to tell you how much links from sites are worth.
Make sure directory submission is done manually and again - get the right price.