I own a very highly modified Benchmark DAC1 HDR. It has great bones such as a linear power supply and good DAC chips. However, it has really cheap computer power and filter caps, regulators (50¢). I replaced them all with audiophile quality caps, $50 regulators and a new audio board, among other items. The result is a very high end unit ($10K) at under $1400. Similar for less money using an Emotiva DAC from 2011 which selling for half the Benchmark, about $1000 converted (no room for another audio board).
I would be suspect of many less expensive DACs unless they include higher end components (just like my discussion about transports-cheap computer based transports generally result in inferior sound as audio transports).