A pay per use in Adobe products alternative

I know many people (including me) that use open source tools, because they use this tools a few times a month. Not frequently. So altough they could choose adobe tools, the price by month is not affordable to they because maybe they uses the software four times a month.

If Adobe could support the pay per use like some Google tools, a lot of users could migrate to Adobe tools, because if you use the software a lot, the payment was bigger than if you use the software only a few times.