Good entry level cd?

I'm looking to buy a good "first" cd player. I'd like to buy used and spend $200-300. My equipment is...Aragon 2004 mkII, Yamaha rxv-659, heartland cables, and a $80 Pioneer dvd. Any suggestions?
Does the DVD have digital outputs?

If so, pick up a decent used DAC and just use that with the DVD player for the best sound improvement for the $$$s.
Quickly scouring the DAC and CDP classifieds, I'm discouraged that your budget will allow for much of an upgrade. There is a Rega Planet in the ads for $300. If you're determined to upgrade now, I would take a look at the Rega (I have no relation to the seller). Otherwise, I would strongly advise trying to save at least $500 or so and then began your search.
Cambridge CD players are good at this price range used.
There is a great deal on an Oppo 980H right here on Audiogon. This unit punches WELL above it's weight and will give you universal capabilities as well as a stunning picture. For $120, pretty hard to beat that Oppo...Spend the other $150 or so of your budget on some nice cables and some isolation devices...

Used Music Hall CD-25.

You could probably pick up a used NAD C-542 in the $200-300 range.
In your shoes, I'd save a few more dollars and wait until a Rega Planet 2000 was available here. There's one for $650, which puzzles me a bit. Apollos are going for a few dollars more than that.

If you need something immediately, I agree with the players mentioned here. An original Planet would probably sound better, but they're a bit old and transport mechanisms only last for so long.
I second the Cambridge Audio suggestion. You might use your DVD player into the new Cambridge Audio external DAC. I believe it'll sell for around $400.
Used Teac vrds 9, 10, 20 cd player. Very dynamic and robust sound. That probably would make a difference compared to your current dvd player.
Used Audio Refinement CDP. Change the power cable and it sounds great after that.
I was recently blown away by the Playstation One with RCA outs.

I kicked the OPPPO 980h on its booty. I thought the OPPO was a good player, until a $12 ebay playstation came in the mail.

I really recommend to try that first.

Stereophile did an article on the original Playstation, but that's deemed Class C, so it's pretty high end. You might want to try out a Fisher Price cdp, and run it to a DAC. A good start. ;)
Ok, seriously, I have an old NAD player which is pretty good for a couple hundred bucks. There's a couple on sale now for under $300.
Let me narrow this....the Aragon I have really lays the bass down. It's got a super fat sound, akin to an old analog synth. It lacks control in my opinion. It's a muddy sound at higher volume, in spite of that being a supposed forte of the Aragon. Right now I use the digi-coax out to the Yamaha for the dac. My biggest complaint is lack of mid-range and possibly top end. I'm afraid of the nad a little, I think I'm after something a little bright and snappy. The Cambridge sounds interesting. I've read posts about them having good bass, curious what that would do for me? Would it clean up my bass issue or would it be too much emphasis on bass? I think I want to go with a universal player because I will use it for movies if it's capable and I've never listened to sacd, so I'd like to try it. Right now I like the sony dvp-3000es, a Cambridge dvd89 or 540, maybe a Denon 2900. There's a rotel rdv-1080 that looks interesting. So any suggestions?