I think there are tons of fun to be had at this price range. Depends on what makes you tick. I enjoy testing/trying equipment out, and so I buy DACs and sell them on if not happy with them or need new functionality. Some old DACs sound pretty good - Rev has a PS Audio DAC from the 90s that sounds scary good. But it handles only basic digital formats.
I think it also depends on where you get your music from. If you are interested in listening to hi-res files from HD Tracks or Acoustic Sounds, an older DAC may not work. Right now I am using the Focusrite 2i2, which only handles up to 96/24 files, so that is what I get from HD Tracks if I buy. With 2i2 I can record vinyl straight to digital at high resolution, something only (or mostly) pro-audio DACs do, but since I like that functionality, that is a great DAC for me.
Note that music is now available in SDS format - the newest highest res format. It requires a new generation of DACs and software to work with them. Read up on that if you are interested in it. I listened to a demo and it came pretty close to making vinyl sound just ok.
The other thing to keep in mind if you listen to music from your computer through a DAC (or plan to): iTunes is not the best player out there (and will not play all formats). I am using Jriver and that made a big difference in the sound. There are threads on that in the archives, feel free to resurrect - I enjoyed re-reading this one.
CTD