At this price range a used transport/DAC combo would certainly yield superior results than any single box player.A Forsell Air Reference transport ($4000 used) and a Kora Hermes DAC ($1500 new) will make the finest single box player sound like a boombox by comparison.
Look into the Gryphon or the Electrocompaniet EMC-1. These will give even the best separates a run for their money. I own top Goldmund, and I was quite impressed with the performance of both the Gryphon and the EMC-1. Goodluck.