It doesn't stop. Sorry about your wallet.
I had two things really bring my system together.
First, make sure your source is up to the task. Junk in = junk out. While I too fall into the not sure I need a CD player camp, I do enjoy my DAC (Benchmark DAC1-HDR). That piece brought massive improvement to both my speaker and headphone systems.
Second, when dealing with monitors, having some solid speaker stands really helped. I'm not sure I reaped a tangible benefit from equipment stands, but resolution and separation certainly increased with some high mass speaker stands.
Good luck and enjoy the search... that's part of the fun.
-Chuckie.