Understanding performance, errors, and costs of data products is tedious and difficult. PAMS is a set of packaged tools to aggregate data from data products to solve this problem. Sure you could build PAMS yourself, but why would you when phData provides it at no additional cost.
Cloud services can drastically reduce costs by charging you for actual use. However, none of the services have robust costing dashboards. With PAMS, you can gain deep insight into what your costs are coming from.