"Upgrading before that is waste of money and ignorance of what you try to evaluate because you try to evaluate his quality in an uncontrolled room."
I don't believe there's much more I can do (beyond rugs, curtains, soft furniture) to control my room. Nevertheless, the sound of my system has continued to improve over time, via gear upgrades.
I'd agree that upgrades that do not produce significant improvements could be deemed a "waste" and that lack of improvement could be attributed to "ignorance".
In other words, if I had no idea regarding what, exactly, I wanted to improve and just bought gear randomly, hoping something would somehow change for the better, that would be wasteful and ignorant. But that's not my approach. I can't afford that approach!
I don't upgrade unless I can clearly identify what it is I want to change and I do a lot of research. Also, I generally will not buy anything I cannot return. My main goal the last time around was improving bass grip and clarity in the lower mids. Replacing the integrated I had with a Hegel H390 proved massively successful in these areas but also, dramatically improved resolution, overall. Speaker/amp matching was so much better that it was as though I'd gotten a new set of speakers along with the amp. I am not speaking of subtle improvements, here.
Would I prefer to have a better-controlled room? Sure. Should I therefore decline to attempt to make any improvements in SQ via gear upgrades ? Not in my opinion, based upon the success I've had so far. It may well be that I will reach a point at which I can no longer compensate for weaknesses attributable to the room. But if I had never tried upgrading gear, I would be tolerating much, much poorer SQ than I enjoy at present. The same would be true had I never begun participating, here; there is no question that AudiogoN forum members have been instrumental in the gains my system has made.