Does it ever end?

I agree with @ghdprentice   Go big or go home. Do it right the first time (Or at least for a longer term)  I just went through this just as he describes. My last few touches were power cords and vibration control. (Before that it was cabling) All of this after I got the components I could afford that make me happy. Good luck!

I can relate to the OP's thoughts, I'm not sure it will ever completely end because technology advances and the allure of something "better" will always be intriguing. I think I'm close to the end of "big"  upgrades. The key for me was finding the sound that really checks the boxes for me with the fewest compromises. I could go for bigger and better of that sound, but no longer feel the need for something different. So, given my age, I doubt there will be any more makeovers, but I've thought that before.

To paraphrase Santayana (some say Plato), "Only the dead have seen the end of upgrades."

I have thought multiple times I was done with upgrades, alas not to be.

However, the one thing I have not wanted to update lately are cables. Specially solid silver cables. They take soooo long to break-in, it's a real PITA.

I feel plenty content now, but at a very high cost.

If money is a concern, treat your upgraditis or go broke.

I have a solution. Add another hobby you are just as passionate about (motorcycles for me) and voila! Your disposable audio funds are now redirected.

I completed a big upgrade back in April of this year and I'm at a plateau on which I am quite pleased. Everything is broken in and the music listening is sublime. As ghdprentice said; I'm good for at least the next seven years or so.