The premium content included is listed on the features tab of the extension library page:
There are 4 templates and 1 starter kit currently included. The plan is to extend this list over time, just as our current extensions come with the subscription - and those will be expanded over time. I believe these have been listed since the subscription program went live so I don't think there should have been surprises around this content for buyers.
To answer the original question on this thread, we produce our own starter kits (tutorials).