$23K is a very good offer for this site.
I just realised it was a few months ago (Oct/Nov 2008) it was stated to me vi PM’s that the site made $10,000 a month and the asking price was $150,000.
Are any of the inbound links to the site from a network that you own? Are they all permanent as far as you know?
What I’m trying to determine, is whether any of the links (which result in your ranking) are likely to disappear in the near future – if they are from a network of sites that you own, will you, at some stage point them to other sites of yours instead of this one?
Previous sold site by same seller slotmachine.org was Top 10 in Google for “slot machine” and since sold I cant even see it in rankings.