The cost of electromagnetic launchers, i.e., coilguns and railguns, is determined by the cost of generating and controlling powerful electric currents. Capacitors and batteries are suitable for small scale experiments only. At present, the most economical power supply is a flywheel generator, e.g., the compulsator. The cost of electric switches is about 1 billion dollars per 1 ton of cargo.
Mass Drivers Cost Far Too Much