Are you paying too much?
Easy to determine if you have confidence in your listening ability. You own a DAC which you say sounds great. Presumably it has a high quality well engineered power supply. Why not buy one of the inexpensive excellent measuring DACs touted by ASR and “listen” to it and compare to your DAC.
I don’t think it works that way, unless maybe one brings their own ear phones.
The room and the music have a huge effect, so the idea of being able to AB with an hour or two of time is not going to happen.