How much does power amplifier really matter comparing to other hi-fi components?

I put 1/3 rd into speakers since they are what determines the Sonic outcome and it’s quality in build,drivers,and Xover are 
what determines its tonal accuracy and naturalness .$10-20k
The Source  such as the dac $5-7 k is equally important in quality 
since the music starts there , makes or break the sonics upstream 
accuracy in the original recording , I feel you just need-to spend more with these 2 areas,  while not sacrifice the quality of a good 
integrated amp, or amp,preamp,$7-10k and very respectable cables around $ 5k in cables for all cables is pretty respectable maybe a bit more ,this is good quality mid 
Audiophile cost quality , by today’s pricing, if you can afford more 
that's great. 

Source and speakers first. Whatever remains should go into powering them. 

“How much does power amplifier really matter comparing to other hi-fi components?”


Lots and lots.

Lots of variables to consider, particularly speaker sensitivity and listening levels. 

Generally speaking, you never want to get even close to maximum power, even with short peaks because manufactures usually specify amplifier power when it reaches 1% THD. THD often rises quickly once you get close to maximum power, so keeping 10% below rated power is generally fine and is often close to minimum THD+N.

Provided you are willing to always keep the volume control well below maximum, consider a higher rating than speakers as they are can accept term short peaks without damage.

A good starting point, but always check specifications.

the secret is that speakers are the most important element ... BUT YOU SHOULD SPEND MOST MONEY ON THE SOURCE ...