As pointed out, you do not need to spend a ton of cash on a good (USB) DAC, especially if cosmetic issues are not that important. Along with the usual suspects, offering some choices in the $1000+ categories (Wavelength, Empirical, Apogee, Hagerman, and others), there's also a large contingent of both DIY and Low-Tech designs coming out of China, based on excellent NOS chips, and sound design. Tvad recently pointed me to one he's been trying with great results, made by MHTDLab, and reviewed
here on Enjoy the Music. These sell on eBay regularly, the USB version of the Constantine, using the TDA1545A chip, as does the Paradisea tube-buffered version Tvad has. The USB Constantine is $399. There is also another USB DAC he sells based on the TDA1543 chip called the Dialogue II that is $299. This is the same chip used in the NOS AudioMirror DAC that has garnered some outstanding real-world comments both here and on other sites. The board for that DAC is also outsourced from China, and is available as a full on reproduction of the AudioMirror design as the
DAC-AH which can be purchased for under $200 direct from China (not a USB DAC though). On the MHTDLabs units, Grant told me he got his in three days from Taiwan, superbly packed and without a hitch. The guy's abundant 100% positive eBay feedback suggests this is the norm. Grant seems to like his alot - perhaps you can contact him if it interests you to pursue further, or he can chime in here. If you are a DIY guy you can get kits to build a dimilar DAC for much cheaper. I won't go there as I doubt that's what the poster is looking for.
Marco