I think selling diy amps is harder than commercially made retail amps…the unknown and not having an entity to go back to if you have an issue.
For the most part all the DIY amps I have are solid state and they just work and will most likely work longer than most of us!!! LOL.
I have built and sold several, one is in France, one in Thailand etc…still going strong.
The neat thing about DIY you can get a really great amp that will provide performance that rivals retail products many times more expensive.
Also you get to have an amp that few others have…
Alex