re testing fees: I formerly worked on an agricultural chemicals and pharmaceuticals site where testing was done trying to find new safe products. Quite an eye opener seeing how many people have to be paid to keep the greenhouses, keep the animals and fish tanks going, do the planting and crop care- and those are just the bottom rung workers. Then the scientists and all their lab workers. Then those of us who were in health and safety, and the personnel people, the legal people....on and on. All that to get a few new products on the market every couple years. The number of chemicals that fail the basic tests eg harming fish are astounding.
So that is why a company won't put research money into producing for a limited market.