Some good points being made.
There is a lot of work into getting these seeds out of country. It takes work. Plus it seems fun and all watching the vids of Joe exploring, but I'm sure there's parts of it that are costly or dangerous. Talking to another Brazilian fruit collector, things can go shit very quickly. He was out of touch for several months. Only after a long pause in communication did this person reach out back to me saying that he was way laid by chikungunya virus. If you google it, I'm amazed my friend didn't die. Taking that into consideration, I would see it as being factored into the seed price.
Personally for me, there is a price limit before I say I can't buy a seed. Does Joe have those seeds that I feel I can't justify paying for at the price he's asking? For me at this point in my life yes (well, maybe I might change my mind later on tinctoria), but knowing the background on this species with the anecdotal experience in collecting it, this definitely gives value. If you can't afford it or think it's a rip off, that's fine. If you can wait xxx years before the first guys in the states can grow and fruit it, then by then you'll see the price drop to a level that you can afford.
Good luck Joe. You are definitely bringing value to the knowledge set of these fruits that you're newly introducing or re-intoducing. No one knew anything about the Plinia clausa beyond that one random pic sellami used for his initial sale. Now the knowledge bank at least in the English language has expanded many fold.