Affordable anti-jitter device

I think you'd be better aiming for a reclocking DAC such as the benchmark. You get state of the art reclocking and a state of the art DAC. Used they run about $700, which is not too far above your budget for DAC and DIP.

My own setup is a Monarchy DIP classic feeding a Monarchy 22A DAC, and I'm very pleased with the sound. The combo comes in at around $450 used. It is pretty much comparable with my Rega P3/goldring 1042, if that gives you any indication, and not far behind the Benchmark DAC.

Monarchy DACs are somewhat out of fashion, but, having removed the lid from mine it seems like a very solid design with top quality components (like PCM63K DACs) that used to sell for $1000. You can pick them up now for $200-$300. However they are sensitive to jitter and benefit greatly from the addition of the DIP.

I've used and enjoyed the DIP and thought the original was more effective than the upsampling version. I've also tried the GW Labs and Perpetual Technolgies units. I didn't care much for the Perpetual unit but to be fair, maybe it required a much longer break-in period than I gave it.
The best external de-jitterer I've ever used is the dbx Quantum mastering processor. De-jittering is only a one function of this box but probably the only one that is applicable to audiophiles.
What I use now is by far the most cost effective solution I've found. It's the Tent X03 reclocker. I installed it in a Marantz CD-67SE and the results are incredible. The downside is that it must be installed in a standard redbook player and that's not particularly easy to do. If you are unfamiliar with component level work on players, it would be necessary to find someone to do it for you. However, the results compete with truly high end players.

I agree with Avguygeorge - look for a DAC that can deal with jitter well. With respect, I would have to disagree on the Benchmark being state of the art reclocking. The claims might be grand but the method is cheap and cheerful. The Benchmark uses a simple and relatively common trick of introducing a cheap asynchronous sample rate convertor into the signal path - which does reduce jitter, but at the expense of changing the signal. The method is used in several other inexpensive devices such as the Bel Canto DAC2, some of the Bryston DACs and the later DIPs. One might call Anagram Technologies state of the art, and it uses the same method (not the same cheap chip though) but with considerably more processing power. But state of the art should go to those methods that achieve great jitter results AND preserve the original bits all the way to the DAC processor, such as word clock synchronisation or synchronous reclocking with buffering. Most of the state of the art methods are perhaps way out of the price range of the gear being discussed here, except for the new Lavry DA10 which brings asynchromous reclocking with buffering down to the $1000 mark and so is probably an item to look at. I haven't heard one but apparently they sound close to the Lavry Blue, which makes me want one. But I have to say the cosmetics will worry most audiophiles, including me.