First of all, this never dawned on me. It makes sense now that you bring it up, but I never thought of this before. Therefore, the only tip I can come up with is not to sell what you grow.
I do know one thing though. Trademarks on pharmaceuticals typically expire after a certain number of years, and when it does someone can make and market the generic equivalent. Like Nyquil. They make cold medicine and, now, so does Equate. When Nyquil first came out, that's pretty much what you got. Robitussen has been out there for quite a while as well but I think their ingredients are different enough that they could make a trademark and not infringe upon Nyquil's. Equate is cheaper because it's the generic equivalent of Nyquil even though the ingredients are pretty much identical. And it came out, I'm assuming, because the Nyquil trademark elapsed.
I would think that horticulture operates roughly the same way, but, again, I really have no clue about that. Just replace those brand names with brand names in the horticulture industry and see if all that just made any sense to you.