I think it depends on the complexity of the parts you're going to make, the number of axes you need control of, number chucks, size of billet etc etc. You really can chuck as much money as you like at these things. For an industrial 5-axis machining centre you'll be starting at several tens-of-thousands and go up from there. Unless you are planning on multi-year pay-back with continuous production, sub-ing out batch production would be cheaper. IME/O.
Would you be looking to supply the NC code, get them to develop it form 3D model, or work it up from 2D drawings and test the cut-paths?