why do expensive amplifiers produce a better soundstage

@irjones 

Because it probably has negligible impact on imaging relative to other influences?

Surely, those expensive produce a better soundstage. However, this is not. 

The DIYer's do have passion in building the super amp with top notch performance. 

Adequate power to negate frequency shifts due to speaker impedance variations.  This doesn’t necessarily require that the amplifier be expensive but some things to look for are a robust and quiet power supply, adequate power for the sensitivity of the speakers being driven, and the ability to nearly double power into lower impedances, which is more critical when used with hard to drive speakers.

OP  expensive amplifiers produce a better soundstage

You should be aware that the soundstage here is only in the electronic unnatural sound world term. It’s not the same music we hear from recording studios or concerts. It’s a purely imaginary sound art. To non-a’philes, it’s just ear-hurting distortion noise veiling the real music. Alex/Wavetouch audio

OP

In my Opinion, soundstage is not really a relationship of Cost of an amplifier

as others has posted and their thoughts, for Me, it is about the ROOM and the system synergy. I was on this quest for a few years and really wanted it . I had to compromise as my room is a bit small / medium. I was able to attain what I was looking for. 

Yes, my gear is a little bit more $$ but that soundstage will disappear if not for the room tuning and synergy that i was lucky to chance upon. I have heard music from amps more money than mine that has a bigger soundstage and In retrospect, I also heard amps that more $$$ than mine and has NO soundstage.

in the end, as i stated, it about synergy and the ROOM