The Grid computing vision promises to provide the required platform for users to run a new and more demanding range of high performance computing (HPC) applications. However, the performance i.e. the response times achievable from the grid systems, is reported as not very satisfactory. End users may be forced to purchase, maintain and upgrade their own dedicated HPC systems for the execution of their applications, which could be a far more expensive solution. But is there an alternative option? To answer this question, this paper carries out total cost of ownership (TCO) analysis of a private resource system and dedicated large HPC system. In particular, we detail the specific costs of a private resource system from a LUNAR project, a large dedicated HPC system from the Lawrence Livermore National Lab, and international EGEE grid project. With this data, we compare the performance and cost-benefits of a dedicated HPC system in contrast to a private resource system. Our evaluation demonstrates that a small private resource system with renting capability can provide a viable alternative to users to run their HPC applications, without the need to purchase and maintain a large, dedicated, HPC cluster system.