Speakers under $50k that rival $200k+ speakers?

I agree with Eric. I’ve heard a number of mega buck systems and they had their sound signatures unique to them and they all sounded fantastic. I also think there is a law of diminishing returns with performance and cost. If you’re creative you can actually best the sound of these systems because you can overcome one of the biggest issues namely the “room.” 

- Steve

If you restrict bass and max output, you can get amazing towers for $3000-$5000, such as the Ascend Acoustics Sierra Tower with RAAL upgrade.  
 
There are very heavy diminishing returns once you go past $5K. Will a $20K speaker sound much better than a $5K from the same brand, sure, but does it sound $15,000 better? 
 
The Revel F228Be for $10K is amazing if you don’t care about bass. 
 
I always recommend subwoofers (unless in an apartment/condo), and I also recommend dual or more subs, as they are easier to integrate and sound better due to the benefit of room mode cancellations. 
 
For $16K you can get the F228Be, dual Rythmik G25HP’s, and $1000 in room treatment, that would be an amazing system.

Anything installed in an air cooled 911 under $49.999999 K

https://www.stereophile.com/content/tidal-audio-akira-loudspeaker

I'd like to hear the Akira though. $70k in accuton drivers. Yeah, it's 215k, but if I was a 0.1%er I'd buy these.

Tidal speakers without a doubt