I’ve found that even the base Shunyata Venom V14 power cord makes a noticeable improvement over stock power cords on a DAC. I think the benefit comes from better shielding of electromagnetic interference. That could be a good starting point.
FWIW, not every "audiophile" power cord sounds good. I’ve heard power cords that made my system sound worse than with the stock power cord. Matching the characteristics of a power cord with the characteristics of your components is important to do. The Shunyata Venom seems more neutral in its effect on all equipment.
A good way to then test out more expensive power cord at low cost is to use The Cable Co's lending library of cables to see if you can hear any improvement over a Shunyata Venom.