$500-$1000 to spend on a used CD player

There is a Resolution Audio CD-55 for $775 just listed. Excellent player at that price.

http://www.audiogon.com/cgi-bin/cls.pl?dgtlplay&1288189439&/Resolution-Audio-CD55-trade-?-

without being able to listen to the Oppo I would be nervous about purchasing it new sight unseen.

FWIW, the Oppo should be easy to sell if you don't like it. The 83 and 83SE both have incredible resale value. The only thing you risk losing is not being able to hear it in your system ;~}

If what you really want is a dedicated player, the Naim CD5x is superb, and you can find amazing deals used (there's one listed now for $950; I have no relation to the seller). I had a Music Hall cd25.2, which is excellent -- very transparent and clear. In my system, the Naim is better than the MH in every respect (as one would hope given that it listed for 4-5 times the price), especially on recordings with mediocre sound quality. If resale is a concern, though, you'd likely be better off with the Oppo (which I haven't heard). Used prices on cd players seem to be plummeting (for obvious reasons).

I'm not necessarily concerned about resale. I just don't want to buy something I haven't heard and then be stuck with it.

They don't come up for sale that often, but an Exposure 2010s or 2010s2 would make a fine player. I upgraded from a 2010s2 to a 35th Anniversary Rega Apollo recently. While I prefer the Apollo's sound, the Exposure more than held it's own and in fact was a more energetic player. My Apollo, like many Apollos, has glitches. It won't always do what you tell it to. The Exposure never stumbled in that regard, or had trouble playing a disc.