I have sellers remorse far more than buyers remorse - I have downsized my system over the years. going from mark levinson pre and a plinius class a space heater to a primare amp and pre. still very good but nothing beats class a power. I sold 802M and built seas thors but that was a slight upgrade,

what are you trying to accomplish? If you want to enjoy audio as a technical hobby there are many ways to do that and it can be quite rewarding. my hearing is not great -many years in a very noisy environment but I do enjoy listening, I build some diy speakers and turntable plinths and spent a lot of time on diyaudio.com I use measurement and listening to get the speakers the way I want them to sound and it is a great hobby. It is one of those hobbies where you will never master it but you can learn to accept the compromises of physics involved. If you are more electronically inclined you can build amps or even turntables.

yes I bought a used set of thor drivers and crossovers with a lot of help for diyaudio and thought i thought I would build a quick set of cabinets and try them out, within a week I put my b&w 802 Matix up for sale, I will eventually rebuild the cabinets and actually finish them it has only been 12 years.

Speakers number one no question and placement is almost as important as the speaker itself. the cartridge is important as well. I had a plinius class a amp for a time and that made a big difference but not as big a difference as better speakers. wires matter up to a point and that point is thick enough to carry the sound and bi wire or bi amp make a difference because it separates the sound so the crossover does not have to. just my opinion. vinyl will always sound different than the digital sources. not always better but often better.