With a specific realization of the transmission line magnet and associated subsystems one can begin to address system optimizations and total costs.  Differential cost tradeoffs such as cryogenic operating temperature, pole tip gradient vs. aperture, how hard to push the steel into saturation, pressure rating and pipe thickness vs. relief valve spacing, etc. can be examined with a reasonable cost model.  An elementary cost model based on unit costs of materials (plus a fixed assembly cost per part or per pound) is a good first approximation.  It expected that (M&S + tax) will give a reasonably accurate assessment of magnet costs for warm iron magnets (such as the Main Injector magnets in which more than 90% of the costs were M&S).  It is unclear that this is as good an approximation for cold-iron magnets such as the LHC and RHIC dipoles where final assembly costs have proven significant.  For magnet associated subsystems the most reliable cost estimates can be taken from recently built machines for which reasonable cost accounting discipline for individual subsystems has been maintained.  Examples of these are warm iron correctors and power supplies, beam vacuum systems, and recent cryogenic plants. Effort has been expended to collect these unit costs for the design study of the VLHC injector based on transmission line magnets.  Two significant conclusions from this work are that factory-based labor is cheaper than in-tunnel labor, and that subsystems which do not exist do not cost cost very much.