I would be more interested in knowing if the domain would keep its PR after being dropped and re-registered.
It's worth very little or nothing just for PR. The real value (if any) would be in the actual domain name.
Agreed. But I would lean more on the PR just for the fact that some SEO work has been done. So the name is out there. It might be what you feel the site is worth as well. Ok so you have a domain with PR. But what traffic and revenue you bring in as well. These are things you need to factor in as well. IF little or no traffic/revenue, than I would say slightly more than the registration fee. And also have to factor in the domain name as well, overture etc. If you were to buy a dropped and or expired name. Do your research, I might be best to keep to the subject matter that the original domain had or some kind of relevance to the domain name as well. And yes the PR does stay with the domain after buying it unless you buy a fake PR domain. This is why you must do your research before buying the domain. Other than a fake PR the only other time the PR will change is during Google PR updates. I had bought 3 PR4 domains more than 2 months ago. Made 2 of them blogs and 1 a freebie resource site. All have maintained their PR during this update.
Even i will agree with you, quality sites with good PR stabilize the PR of the site there is no a certain amount for PR sites It's an overall factor with all popularity data together with the quality of the name itself Check my thread to have an idea http://forums.digitalpoint.com/showthread.php?t=300546
so it looks like i can expect Reg fee upto Low $xx for the domain.....and yes the domain is brandable if used for the correct purpose
Does the site have good content? What you can do is re-register is.. (it's not a lot, no more than $10 a year) and then sell links off your site... you'll definitely earn over $10 for a year's worth of sold links.
Its not just the domain name with PR4 but surely about the contents too. As someone adviced, you can make good amount ( Since you are from India ) even if you sale links @ $7-8/month