Looks like I'm a little bit late to the party, but I have had an Onkyo C7030 for about a year and a half now and this looked like a relevant place to share my experience with it. Maybe it will help someone else make a decision in the future.
Anyway, I bought mine new off of Amazon for about $140. I had never seen it cheaper, so I bit. I am a pretty young, first generation "budget audiophile", so I have not heard any other CDP's in my time. However, there has never been anything that has stood out to me as wanting. Not even a bit. I first used it in a system with a pair of Teac LS-H265's (on cheap Dayton Audio stands) and a refurbished Denon AVR-E200, which is about as budget as you can get. But it sounded WAY better than anything I'd ever heard, given that I had only experienced MP3's prior to that. I've since upgraded to Elac Debut B6's, a Music Hall A15.2, a Musical Fidelity V90 DAC, and about $200 worth of interconnnects borrowed from a buddy and the C7030 has kept up brilliantly. It's only being used a transport, but it is incredibly reliable, durable, quiet, and "HIFI-ish". In combination with the MF DAC, it sounds absolutely amazing to me, with huge detail, spaciousness, and enjoyability. I guarantee that if you're comparing a $1,000 system using this CDP as the source, it'll crush anything using MP3's, cost notwithstanding. I've compared my system to some worth over $10,000 using MP3's (PSB/McIntosh and GoldenEar/NAD) and my setup killed them. It's obviously due to an inferior source (the old garbage in, garbage out concept), but all that to say that if you're looking to make the jump to a better source, you will almost certainly be thrilled with the C7030.
A word on some of the QC issues people have brought up. My player has zero buzz, hum, or clicking. It also has no trouble with scratches on CD's. I use a lot of CD's from the library, so they're pretty beat up, but the CDP has never once given a single trace of an issue. I've had zero issues with it, period, so if you've experienced anything otherwise you probably have either a defective unit or an issue with another component in your setup.
Sorry if this was long-winded or overly subjective! I just hope that it helps at least one person jump the MP3 ship and learn how magical music CAN be without having to spend a king's ransom.