Adding even a few well placed and sized panels increased my enjoyment of my current setup for far less than any $5000 power cable, $3000 usb cable, $10000 set of speaker wires or $500 fuse ever could.
That is the most well kept secret in audio. I don't know who is at fault though. Dealers that profit from the upgrade cycle caused by bad acoustics or simply "audiophiles" that enjoy pulling the trigger on stuff you plug in but don't know what panels to buy or where to hang them.