At linode that kind of money will give you 4G of ram, cpu power in the same ball park and loads of storage and transfer. It seems that Backends - and the GAE in general - makes most sense when you view the system as a whole, and work with systems of a certain size. Tasks goes in to queues and backends are started and stopped as needed - stuff like that. If all you need is to serve a long running process, linode and the like is more economical.