Hello André,
clearly the prices are already high...
But the effort that Alan Galloway and Bjorn Malkmus-Hussein put into the discovery of new species was not small either; the two were often on the road together.
Impressions of the Laos expedition can still be seen on Alan's page; I hope it doesn't go off after Alan died last year...
https://alangallowaybotanicals.com/travel/asia2015/laos2015/
Bjorn Malkmus-Hussein still has one of the largest Amopho collections and has always offered rel a lot in his shop years ago, but then almost completely discontinued it. I asked at the time and he said at the time that the effort with the care and the propagation was very great and the income was so low that it was not "worth it" and he changed the amorphophallus again completely to private pleasure.
Alan offered a lot of his surplus tubers in the USA and also shipped internationally, until the trouble with customs, phyto and ungrown or not grown tubers was so great that he no longer offered on ebay internally, but only for the USA. But even with the size of the market there, he could only partially achieve good prices and then only partially compensate for his expenses (travel, greenhouse, etc.), as he once wrote to me.
But somehow every private collector has the problem. For example, I spend 800 - 1000 € per year on heating costs in my conservatory and cover this only partly via offers on ebay; but since postage costs have risen so much internationally, the demand is not so great anymore....
A wide field...... Nevertheless:
Happy growing,
Bernhard.