You can make your own fake PR. All you need is for example make a 301 redirect to site with high PR for a such time.
Just to add, google normally does page rank updates on a quartely basis. So be very careful about buying domains that have high PR rating but have no discernable content. Chances are, when the next page rank updates crawls that site, that sites PR will go down drastically since the site has fake PR. PR updates are believed to be run by Google every end March to early April - then quarterly after that.
just do simple query in google info:sitename.com and look out which website shows , if its fake pr you will a different name, if its not a fake you will see same name
Many webmasters buy PR of their site. They find a site that has a PR 8 for e.g and buy a link to their site. After a while, your sites end up with a higher PR and you in turn can sell Pr ; provided the site you are buying from does not have fake PR..