Well I just checked my rugby forum
ScumV Rugby Forum - Welsh Rugby Forum - Rugby Chat at its Best :: Index and it tells me I have PR zero , have 9 backlinks in goolge, none in Yahoo (yahoo have limited access to their site: & link: features.) it also tells me some other things.
Here is the rub though.
My domain is a niche website aimed at rugby.
It is number 1 on google for welsh rugby forum,
It is #2 for the term rugby forum.
It has over half a million posts,
in one month during the 6 Nations this year we got 3.5 million page impressions.
It is a domain name over 4 years old
it is in dmoz twice
They say it is worth $532

I refused an offer of £10,000 for the site last year.
In short, it is using ALL the wrong elements to base a value on.
In answer to why i was offered £10k for it. next year the British & irish lions are touring South Africa. At LEAST 30 members from the forum are travelling over on tour to watch the matches. TYhey are paying a tour operator £7,000 plus (each) to go. That is £270,000 of business. The tour operator that offered me the money will make his money back in no time!