One of the main arguments for the use of cloud computing is its dynamic nature. Used resources and therefore also the costs are based on actual usage. However, as simple, clear, and cost-effective as it is to quote prices for the hourly use of virtual machines (VMs), it gets complicated when additional components are used. Few users rely on VMs alone: network connectivity, storage, software licenses (operating systems, middleware, databases, and applications) – a large number of components have to be taken into account for complete IT environments. Self-service also means that costs need to be kept an eye on.