About speakers being most important: it depends.
For years I upgraded electronics while keeping the same speakers. When I finally got some loose change, upgraded the speakers by an order of magnitude and at last discovered how just good my amp and preamp had really been all along.
The old electronics, however, couldn't handle post-CD digital. So when these were traded for contemporary equipment, the tables were turned and the speakers again became the weak link -- I was right back where I had started, albeit on a higher plane.
Now, $12k later, everything is in balance and to date I'm resisting the urge to upgrade further. Powerful temptations aside, for me the present is the logical time to pull the escape cord from the rabbit hole. Famous last words, I know.