Have you done any calculations as to what it would cost to rent say, 20 x $100 a month dedicated servers spread across multiple datacenters, that can do virtualization with OpenVZ, Xen, or KVM (takes care of network, power, bandwidth, hardware issues) vs. what you spend monthly with AWS?
Bluntly it seems like you must have spent some dev or ops time learning all this and migrating away from EBS etc. even if you didn't hire someone.
Frankly, if your bills are greater than $3K per month with AWS I question whether you are truly saving anything.
(I figured that midsized instances vs. dedicated servers are about 5:1 in terms of performance)