Hi rjr...
If you are a person who can hear and appreicate the difference between cables to the point where you are willing to pay for AudioQuest cables, then I should think that you will appreciate the improvements in a better, external DAC. IMO, you should pay at least as much for the DAC as you paid for the cables. ;o)
Personally, although I can hear and appreciate differences in (some) audio components, I am skeptical about differences in cables being worth the cost.