A) That's a bit nuanced and depends on the application you are referring to (there are ~200 represented here), but if you had the scripts and the repos and built from a vanilla AMI, a box would boot and configure within a few minutes. We shortened the boot times greatly by using puppet to configure a template node which we then used to create a generic versioned AMI per autoscale environment and deployed with Asgard. If you had the AMIs, an EBS backed instance would boot and serve traffic in anywhere between 15 and 30 seconds or so.

B) For costs, you can check the FEC filings... I cannot recall what they were month to month, but it will be accurately reflected quarterly there, so you can get a rough estimate. It was like a kabillion times more in October 2012 than it was in June 2011. The important part for us is that the costs scaled with our demand.