You are right, they are all much better than your freebie rubber power cord. Anything, absolutely anything is better than that.
All those other cable suggestions are probably good. There is however only one in your price range that has stood the test of time- Synergistic Research Master Coupler. Originally around $400 back in the 1990's they are still made today and come up used for anywhere from $200 on up. This makes it probably the only one mentioned you could buy and use several years then sell and not lose money.
All those other cable suggestions are probably good. There is however only one in your price range that has stood the test of time- Synergistic Research Master Coupler. Originally around $400 back in the 1990's they are still made today and come up used for anywhere from $200 on up. This makes it probably the only one mentioned you could buy and use several years then sell and not lose money.