Whenever I have compared two amplifiers of the same family but one twice as expensive, the more expensive one has sounded much better (much)... not just power wise... but noice floor and tonal characteristics. So, my reasoning has been, buying two amps of lesser sound quality might get you a more powerful sound... but not higher quality input sound. So I could never get myself to do it.
Theoretically, one could argue that because you separate the speaker components to different amps you get a sonic improvement there. But that it could be greater than the improvement in a much better amp seems like it would be unlikely. But I have not done it.
If someone had actually done a legitimate comparison I would be interested... So same amp brand and kind, two amps half the price of the single amp. I’d be interesting to hear.
If you can simply afford anything, then four top of the line monoblocks for bi-amping I am sure would be the way to go. So, say four Audio Research Reference 330m monoblocks.

