That ballpark calculation only works on a particular subset of systems.
For example, on per-hour services it's nice to bring up big environments replicated for Dev and QA. Or to do incremental updates with full A/B live testing, with the old system eventually replaced.
Also, AWS has many services that replicating takes a lot of effort and planning if you do from the ground up. Like load balancers and monitoring. In fact, it would be smart to play with an AWS system before buying a whole stack of BigIP/Cisco/EMC/IBM.
EBS is terrible, EC2 is dog slow and the relational MySQL thingie probably is unreliable. But everything else has showed to be very stable for a long time with very heavy users.
I'm upset at Amazon's terrible communication, but it's still the best option for starting anything bigger than a php webhosting plan.
For example, on per-hour services it's nice to bring up big environments replicated for Dev and QA. Or to do incremental updates with full A/B live testing, with the old system eventually replaced.
Also, AWS has many services that replicating takes a lot of effort and planning if you do from the ground up. Like load balancers and monitoring. In fact, it would be smart to play with an AWS system before buying a whole stack of BigIP/Cisco/EMC/IBM.
EBS is terrible, EC2 is dog slow and the relational MySQL thingie probably is unreliable. But everything else has showed to be very stable for a long time with very heavy users.
I'm upset at Amazon's terrible communication, but it's still the best option for starting anything bigger than a php webhosting plan.