Whilst offering lift-and-shift deployment and elastic capacity, the cloud also reintroduces an old mainframe concept—chargeback—which thereby rejuvenates the need for performance and capacity management. Combining production JMX data with an appropriate performance model, we show how to assess fee-based EC2 configurations for a mobile-user application running on Linux-Tomcat hosted by AWS. The capacity model can be used for ongoing cost-benefit analysis of different AWS Auto Scaling policies.