I can only speak for myself. As someone who currently has a bunch of systems, I have sold things in the past or given them away, only to have to re-buy. The issue comes in that each system has its own signature sound. I would wait to sell anything. If it sits in a corner for a year without the urge to listen to it again, then perhaps sell. Move slowly to avoid regrets. Again, that's just me and speaking from my own experience.
Selling, it comes down to how much hassel do you want to deal with. You can sell here on the website, or to someone like TMR. TMR, there is less potential problems to deal with, but also probably less money, as they need to make money. Some stores also will take trade-ins.
@rar1 As said above, whereever you live, go and listen to as many other systems as you can. If you go somewhere on a trip, go and listen. Sometimes they will even have a smaller listening room such as what you have. Also, there might be "listening bars" where you are? Your ears are your ears, trust them, not the salesperson. Especially don't trust articles, magazines or youtubes. They can be a great introduction but can also be misleading. Trust your ears.
Some people love high efficiency and low wattage. Others love less efficient but huge amounts of power. More money isn't always better. I have listened to systems that were over $1,000,000 and didn't think they sound as good as my primary. I started with low efficiency and high wattage and my primary system is low wattage and high efficiency.
@rar1 Well said and great advise. Very accurate about tube amps. I have had tube amps fail in the past, up to the capacitors failing in an old Dynaco ST-70. Tube amps seem more straight forward and easier for repair. I have had solid state fail that the manufacturer wouldn't stand behind (Van Alstine) that was given away for parts. Also don't let a sales person intimidate should you choose to do extended listening at a store, or ask questions that they look at you like a fool for. If they have issues, that's the wrong store. The only thing to fear in the whole of the world is GOD. Have fun with your hunt. If you go slow and take your time, you will be very happy.