I use Lucid AD into an RME Digiface for my two track or less work, very good sound and in your price range. Gives you multiple TOSLINK / ADAT ports, SPDIF, MIDI I/O x 2 and an analog output to drive a headphone amp. RME's Totalmix software that's included is outstanding for headphone mixes etc, I can't think of a better monitoring setup.
War