Keep AGOL credits for geoprocessing, but have storage be a dollar amount per GB of cloud storage, just like Google, DropBox, Microsoft, and others. Each user type could come with x GBs of storage, or an organization could just buy a plan that comes with x amount of storage up front. The total available space and cost of storage could be monitored independently of geoprocessing credit usage, in effect helping them plan better for next year's budget.
