Does anyone else besides Allegorithmic sell substances?
Not that I’ve ever seen. Their list is pretty extensive, and rather cheap. The market is also fairly limited in scope, from what I can tell.
I did ask them if I could sell Substances that I make from scratch, and the answer was of course, “Yes”. However, I never really got into it and never produced anything worth selling. And I doubt I’d want to sell it that cheaply if I did.