Hello, Jim.
This looks like a good 'sink my teeth into it' discussion.
I find myself in the midst of my personal audiophile merry-go-round. I restarted this hobby under four years ago, so perhaps I'm still in my early stages.
I added two pieces to my developing system this year that have made big improvements in SQ. I guess I should clarify. One addition (Gustard X20u DAC) made a big improvement over my entry-level DAC Magic Plus. The other improvement (Don Sachs Model 2 preamp) made a
huge improvement in SQ. I'm not certain this preamp qualifies as expensive gear when you consider how much ARC or McIntosh preamps cost, but it is very expensive to me.
After adding the Model 2 preamp to my system in Oregon, I was struck by how it is the best component in that system, and I began thinking about how I could even the playing field by adding a better amplifier without spending $5k to 10k for one.
This is a very enjoyable hobby (addiction?), but it ain't cheap, is it?