Rman9, good on you for using your ears and seeing for yourself.....cables can and do make a difference (to my ears)
Celtic66, for years I also listened to the "cables don't make a difference", then a friend loaned me a set of AntiCables 3.1 speaker cables and some AQ RCA interconnects.....that was a revelation on the value of good cables.
Sgreg1, I don't have a formula as you do, but I also believe in "bang for the buck" in cables. My total system, including cables, is just shy of $16,000. Does a $2,000 cable make sense in my system? No to me they do not. What does make a lot of sense is finding amazing cables at affordable pricing that do make clear audio improvements. There are some great manufacturers in that category: AntiCables, Morrow Audio, WireWorld, Cullen Cables, Oyaide, Supra Cables, DH Labs, Lavri Cables
Dz13, once I realized the improvement that almost every cable can produce, I had to find better Ethernet cables (feeding Node130), USB Cable feeding DDC from Node, and even I2S cable from DDC to Pontus II DAC
If you have true balanced components (as all of my Denafrips products are), definitely use XLR to keep that balanced signal integrity
Rman9, I would try a better power cable as many have mentioned. Even better, add a dedicated 20 AMP line ($200 - $300), a high quality 20 AMP plug ($50 - $100), and a better quality power cable.....that made tremendous gains for me