I sold one on eBay for about $500 about a year ago... The 797 had an inherant clicking problem that Onkyo said was Dolby's fault, and Dolby said was Onkyo's fault.
Go to
www.audioreview.com as a decent source of review's, although some are somewhat influenced by "pride of ownership"...I mean, what are they gonna say, "I just sunk a thousand dollars into a piece of junk..."
. If you were looking for a budget used receiver, go with a Denon AVR-3802 or 3803...for less than $500.
I'm currently selling B stock Factory Sealed Denon AVR-3805's for $650 on eBay!