For $527 its a great deal, My only issue with the 806 is that it should never have gotten a THX Ultra2 certification (have no idea how they got away with it) The 806 has a far smaller power supply than the 805 and failed the Secrets bench test driving a 4ohm load badly. If your only going to use it to drive 8ohm speakers or have very efficient 4ohm speakers then you will be fine.
In addition to the aforementioned neutering of the amplifier section, the 806 has Audyssey MultEQ rather than the superior MultEQ XT and no longer offers upper range Burr Brown DAC's. THX caught up with what was happening in the 8xx series by certifying the 807 THX Select2. It was peculiar that the 806 was Ultra2 indeed. In addition, after the xx5 Series, Onkyo manufactured all units in Malaysia instead of Japan. Integra included.
I really think Onkyo was really trying to make a major statement with the 05 Series and have been maximizing profits with cheaper labor costs by moving production to Malaysia, the changes with the 800 Series, etc.
Still a huge fan of the 876/906/9.9/886 and the current Reon equipped newest models. These models still offer unbeatable features and amplifier sections for the money. Denon's forthcoming 2500 Dollar SSP based off the AVR 4310 pales in comparison to the 9.9. No THX, XLR's, and much more.
The only improvement in the 806 compared to the 805 is it having marginally superior video processing and Audyssey Volume.
Back to the original question, that is a very good price for the 806. If there are any refurbished TX-SR875's available, I would spend the extra money as it is in another league.