A lot of the time projects like this never go into production. It is hard for a lone hobbyist making them by hand to crank them out in quantites sufficient for sale to the public. They need a backer with money and mass production equipment. Since the Apple II platform is so old, I doubt there would be anyone that would offer to put it into production because the investment would likely never pay off. If he did decide to start making them available to the public, they would likely cost hundreds of dollars for all the time that goes into making each one and they usually do this as a side thing, so they won't be devoting all their time to it which means long waiting lists until he gets sick of making them and quits.