This is one of those, “how hard could it be,” ideas.
Vending machines are regulated and licensed by the state. Could one skirt around that by using something like Amazon Lockers only with smaller bins like post office box size?
I envision the process something like:
Identify desired product from some sort of printed “menu” with QR codes
Scan QR code for the product with smart phone
System (web page?) informs buyer if any are in stock
Pay using Square or Apple Pay or Google Pay or some kind of magic fairy dust
When payment clears, door pops open allowing purchaser to access product
Does that still sound like a vending machine?
I know, I know, “who will build it, who will maintain it, who will stock it.” Sounds like a fun project with a lot of hurdles, er, places to learn stuff.
edit: after thinking on it, this sounds a lot like reinventing the wheel