I’m a big fan of the v2 Shunyata products, but given your target budget and potential options, if I were you I’d try the Whisper product. You’ve read the thread here on it, and it sounds quite compelling. (I have no experience with it myself, but if I were starting over, that’s where I’d start.)
Look at it this way: power cables don’t wear out. They will benefit your system hardware for years to come. Get the best you can within your budget and enjoy the results.
The Alpha and Sigma v2 NR cables I’m using have been massive improvements over the factory cables, and even over less-expensive alternatives. They really do provide huge improvements, like upgraded hardware.
Edit: have you tried the power cables from Iconoclast? I know they’re “BAV” branded which suggests more budget-oriented, but perhaps they provide the improvement you’re seeking. You’re familiar with their other products…