For such a (relatively) simple architecture: I agree. Easy dedicated server, make a point to watch security updates. The reason to use cloud-style services is

For such a (relatively) simple architecture: I agree. Easy dedicated server, make a point to watch security updates. The reason to use cloud-style services is so you can focus on building the product quickly instead of building and maintaining architecture. But once the product is stable, a cost-reduction pass is in order.