I can't point firmly to a specific example without spending some time re-researching it, but I know I've read of certain products -- mosquito nets, more efficie

I can't point firmly to a specific example without spending some time re-researching it, but I know I've read of certain products -- mosquito nets, more efficient little stoves for cooking, solar cookers, etc. -- that are adapted culturally to specific markets in Africa, among other places, and which the (government, researcher, or nonprofit/charity) makers of such products found people won't use if they're donated or freely given. Instead, small amounts of money need to be charged for them. When people feel they're buying them for an amount that holds value for them, they value the item more, and trust it more. So I'd say your concept is sound. But there must be some scale to it to actually make any kind of margin, and you'd have to research the numbers to see if it could work.