[tdavis]

Yes, it's probably an order of magnitude more expensive when accounting for the countless hours spent pre-optimizing everything, tracking down intensely opaque performance issues, dealing with the AppEngine team's tendency to introduce changes that entirely alter performance characteristics without notice, and etc.

This, of course, is on top of the now rather ludicrous cost associated with maintaining a write-heavy application that must be both highly concurrent and consistent, with a large number of composite indexes and relational schemes that the datastore was simply not designed to cater to. That isn't AppEngine's fault, but it is by no means a generic hosting platform and I truly believe that their goal of creating an "infinitely scalable" and robust system is directly at odds with providing a product that is a good choice for the majority of applications.