1) Hey, it's your money. True
2) The only reason I can see for $100/foot cables is to impress your date so that you can get her (or him) into the sack. I am a happily married 62-year-old, so I'll spend my money on something else.
What kind of women did you date?? I'm a happily married 44 year old.
3) I strongly suspect (I have the same right to pontificate as the cable manufacturers and the hacks who depend on their advertising revenue) that if you move your sofa six inches to a side, it will have more audible effect than changing from the RS cheapie cables. That is why spending a lot of money on cables is sort of silly.
Moving my couch over 6" would effect imaging and bass response probably. Two of the very things that I find good cables have an effect on. But I see you point.
4) The speaker (including crossover, etc.) is the place where subjectivity, objectivity, and dollars coalesce into the most variable and productive element in terms of final sound. (What if you build a Pi7 out of mdf vs plywood.)
This we are in agreement on. I also believe it is the speakers that make the most difference in final sound. Second I would pick the phono cartridge if you listen to vinyl.
5) Certainly there must be measurable differences between the sound from two different cables, given a sensitive enough instrument and reproduction system. "Can anyone hear the difference?" is another question. I tend to agree that if you think you can, that is good enough. (Wear your copper bracelet and sleep on your magnetic bed if you think it helps your arthritis. I think that glucosamine sufate helps mine.)
Sorry the only magic power source is the pyramid with added metaphysical crystals. If you wear one on your head you won't believe the added depth and transparency of the sound stage. It will also help your arthritis (this is just a joke. See smiley face?)