Doesn't sound all that great to me.
He's only had it for about a month.
Why is he selling?
Unless you can get it for $800.00 or less, I would pass, plus I couldn't deal with the HDMI issue. Maybe think about putting those funds toward a new imac instead. My 2cents...
I might pass on buying it. Do you know when the 2012 iMac's will be released?