Rand Fishkin of SeoMoz did an excellent video on what Google Page Rank is good for.
There are plenty of domainers on domain forums looking for PR domains. Domain wanted ads looking for PR 3 or Pr 4 etc… are posted almost daily on Namepros or Dn Forum.
He explains that the difference in ranking for high pr vs low is not that big.
Its well worth the watch. Here is the Direct link HERE