To offer online bundles of independent e-services, software is needed that composes services of different enterprises into a bundle of services, satisfying a complex consumer need. In earlier research, a service ontology – a formalized conceptual model of services – has been developed for such software-aided service bundling. This ontology, however, did not include constructs to reason about the prices of services, while these are needed to realize and offer service bundles online. In this paper, we present an extension of the service ontology with pricing models for e-services. Examples from real-world services are used to illustrate how pricing models of services can be modelled by domain experts, and prices of service bundles can be calculated by software using the extended ontology.