That cannot be done with in-app payment at all, sorry to say. Think about the big picture: Apple has created the price categories, that are adopted to all currencies of the world with change rates that are adopted only when the exchange rate has changed strongly. To use other prices ist not possible in that system.

To create 1 in-app-purchase for every product that a content provider creates, would mean we would have to create each one "by hand" and align it in the programming. That is an effort that we cannot provide and is sure to create many failures. The problem with the second suggestion: The customer can buy a subscription for a product only once. So you can align a token to it but the user cannot buy a second one.