I too have been working on making my system faster and more resolving of fine detail and have made most of my progress on the power delivery side. I have limited experience with power cables but have tried five different brands in my system in various positions and my recommendation would be a Cullen Cable Crossover Series. I currently have three of these in my system and have found them to preform quite well. I don't know your required length but you can purchase a three foot cable new for $175 with 30 day return, a little more than your target figure but close with a return option. Not sure how often these come up on the used market but would surely be under your target.
Gary
Gary