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

It all matters...if you did a mashup of all the above posts you would find that "it all matters".  

Assigning percentages to components is a fool's errand, you may like to think about it in those terms, but you'll never match it as you move forward.

My simple rule of thumb is that any component that is a transducer requires more dollars.  That would be speakers (signal to sound), cartridge (squiggles to signal), cd/dac (digital to analog). 

After that you pick the order of spending, but it all matters!

Regards,
barts

This guy trying look for good advices and you send him out like drunk girl looking for quite place to sleep a frat house. but it not your fault because op give very little information.
take money you pay for speaker- Raidho and how much you have leftover. That the question is what do you have after purchase the Raidho? That good speaker I have that in workshop system I just cover that tweeter when use machine because ribbon no like dust.

It is a system and the system will only be as good as the weakest link. You can have the best amp but a bad pre-amp and the pre-amp will not let the amp shine. I my self would consider the pre-amp a little more important than the amp. If you have a budget and have to compromise some where in the system chain the pre-amp would be my last to compromise.

I forgot to mention with amplification ,never skimp on quality- power for on transients dynamic range on peaks can be 10 x 
the power in milliseconds and your speakers will dictate the efficiency and what’s required ,balance,quality,and quantity of necessary power . I always look at thepower supplies 
and capacitor reserves on any products , for tubes most important 
theQuality of chokes and powersupplies , and ample size,
in Solid state ,my Coda for example has a potted 3 kva transformer which is Huge ,and over 80k in capacitance , and over 120 amps short term on demand current ,  that’s why it’s important to see the quality and exactly what’s under the hood , just keep this in mind ,and digital at least 2 linear power supplies ,which my M3 Bricasti dac streamer has, 3 even better ,like on their M1,m21 
two good size linear power supplies is ample and my streamer board is included ,with ample filtering and low noise.

Assuming a budget of $10K-$15K, I might put nearly everything into a pair of JansZen Valentina A8 active speakers. Plus as little as $550 for a Bluesound Node (the source) and < $100 for cables.  Then trade up from the Node later (to Bryston/Cambridge Edge/Exasound).  That's assuming I lived within reasonable driving distance of the JansZen shop in Ohio (otherwise, I'd be reluctant to put all my component eggs into their basket).

But suppose a $5K budget instead, as a more reasonable entry point for a "high end" clean slate system. Assume we're going for digital not vinyl. Then very roughly:
1. 60% for speakers (because they make a bigger difference than anything else and are a little harder to trade up due to size/weight);
2. ~10% for a streamer/DAC (such as the Bluesound Node);
3. 30% for an integrated amp (maybe Peachtree or Cambridge Audio);
4. very little on cables (Bluejeans Cable for speaker wire; for everything else, just use what comes in the boxes with your components for now.)

For half that budget, you could build around a pair of KEF LS50 active speakers ~$1250) plus < $1K for everything else, with change back.