Injection moulding of plastics is commonplace but there is a barrier to new product entrance due the high upfront investment required for mould tool manufacturing. This makes the production of moulded prototypes difficult. Additive manufacturing is a possible solution for short production runs, the length of the run being constrained by the speed of production. This paper quantifies how an innovative short run moulding tool manufacturing technique reduces the costs and time associated to the manufacturing of an injection mould tool, making injection moulded prototypes on a conventional injection moulding machine a more economic option than producing a run of additive manufactured items. The same test geometry is made using injection moulding and additive manufacturing. As well as quantifying the time taken to produce a run of prototypes, the quality of finish is examined by scanning electron microscopy.