I don't even look at PR when thinking about buying a domain, though it's nice if there as a free bonus. Reason, it could be here today and gone tomorrow. That is so even if you manage to maintain the links and status quo.
i.e. I have some active websites online for several yrs with the same or more links than they had 3 or 4 yrs ago. A few mos ago they had PR's of 2, 3, or 4 and today when I checked they have PR 0's for no apparent reason, seemingly due to the recent Google reindexing.
Once I put a dropped domain online which carried the old high PR 6 over for a month or 2 but suddenly went to PR 0 even though my site was better and more relevant than old website and the links were maintained and even more added. That site is still PR 0 even today, about 1 yr later.