To improve the sound of what you already have I would get a power conditioner. Get a used Audience unit for about $4k and you can upgrade it as you go a long. When I added a conditioner to my system, it was like a veil was removed from the music. All the instruments sounded more like instruments. Blacker background and better defined soundstage.
Best Bang for the Buck Upgrade
So I have an unexpected bonus coming my way and may want to dedicate a portion of it to a system upgrade. Let's say 5-7k. Current system is Pioneer S-1ex speakers, Cambridge CXC transport, Musical Fidelity A1008 integrated, Burson Composer 3xp dac. Cables are mid grade nothing fancy but better than stock. Not really interested in streaming at the moment.
So for a descent chunk of change what should I be looking at? If I sold the speakers I could probably go up to 10k for another pair (used always) but I really don't think I have come close yet to maxing out the potential of these Pioneers (tad).