Fake page rank
 

Fake page rank is a common SEO trick you should be aware of when doing a number of things from buying an attractive domain to buying page links or adverts.
Domains with a fake PR are often banned from being indexed by google but more immediately important is that many sellers will advertise the domain as PR7 for example to raise the price you pay for it.

When somebody is offering a domain name for sale, they can synthetically increase the domain's PageRank. It is achieved when fraud domains use a 301 or 302 redirects which point their websites to sites with a high PR.