hi... i have a few domains which i found on internet which are expired. They have PR3 but no rank in alexa... All are mostly .COM domains... So is it profitable to re-register such domains and then will i be able to say sell it for atleast double the price i pay for the registration?
Most likely those domains will lose their pagerank in the next visit of the google pagerank crawler. I bought PR5 domain with no alexa rank and it dropped to PR0 after a week. But it can take 3-4 month until it will drop.
That could be web site on the #1 position but with PR. I suppose everything is possible. Might depend on the age of the domain name.
It might be possible, Alexa is traffic rank, PageRank is simply to do with high quality websites linking to your website, even if you do get no traffic from them and have nothing on Alexa you could probably have a good PageRank.