I interpret this question as a variation of "at what point does diminishing returns start to set in?" I take it as axiomatic that any system, from the intro audiophile to those pushing the SOTA, can be improved upon. For me it comes down to a case of incremental money spent and added system complexity versus current enjoyment levels. I look at some people's system pages and they have listed 30+ components (including tweaks) in single source systems. I just don't want a system that has that many variables. Nor do I want to spend $100k plus either. I became an audiophile when $5,000 was a very expensive component and only a single company made a loudspeaker costing more than $10,000. When I listen to systems costing multiples of what my current setup costs I marvel at the sound, but I still find myself perfectly content with what I have.
Among people who post here I suspect I'm a little more forgiving of sound quality than most. To give an example, I recently had to replace a tube in my preamp so I ran the system without a preamp with the D/A going directly into the power amp. I strongly prefer the sound of the system with the preamp, but it still sounded great without it and after a few days of acclimation I really didn't miss the preamp. Push come to shove I could live with my Fisher 400/Monitor Audio Studio 20 system as my only system. That system does everything Dweller outlines in his post. But then again, that's just me.
Among people who post here I suspect I'm a little more forgiving of sound quality than most. To give an example, I recently had to replace a tube in my preamp so I ran the system without a preamp with the D/A going directly into the power amp. I strongly prefer the sound of the system with the preamp, but it still sounded great without it and after a few days of acclimation I really didn't miss the preamp. Push come to shove I could live with my Fisher 400/Monitor Audio Studio 20 system as my only system. That system does everything Dweller outlines in his post. But then again, that's just me.