The pay-as-you-go economic model of cloud computing increases the visibility, traceability, and verifiability of software costs. Application developers must understand how their software uses resources when running in the cloud in order to stay within budgeted costs and/or produce expected profits. Scientific workflows often involve data intensive transactions which may be costly. Business and consumer application developers are likely to be particularly sensitive to costs in order to maximize profits. Verification of economic attributes of cloud applications has only been touched on lightly in the literature to date. Possibilities for cost verification of cloud applications include both static and dynamic analysis. We advocate for increased attention to economic attributes of cloud applications at every level of software development, and we discuss some measurement based approaches to cost verification of applications running in the cloud.