PLM 360 recently updated it’s pricing page, so I’d like to point out a few things that are of interest to API developers.
API development is open to users with either a Professional or Enterprise license. For in-house development, you can use your own Pro license for writing custom utilities. For third party development, you can contact the Autodesk Development Network if you want a tenant and Pro license for development purposes.
Sandbox environments are available. This is very useful if you are writing an app or integration that modifies data. Speaking from experience, you don’t want to debug on live data. A sandbox environment is a clone of your live data. So you can develop and debug your app without the worry of corrupting "real" data. You are allowed one data refresh per month, so you still need to be careful.
Sandbox environments can either be on the regular production environment or on a “Preview” server. Preview tenants run the beta code for the next release, so you can see changes before they go live. This is useful if you have an integration that you need to keep healthy. A Preview tenant can be used detect breakages before they happen. At this time, I don’t have details on how much lead time you get with a Preview tenant. I think it varies from release to release.