It was expensive, but it was far more than your average helicopter. Low Observability was one area, but actually the NBC threat (Nuclear, Biological, Chemical) drove the design to pressurized cockpit with a very complicated Environmental Control System. The Computers, FCC and MEP- Mission Equipment Packages, although state of the art then, were expensive and heavy. Turn the air vehicle design back on without those constraints, with updated and simplified FBW controls, and it would be obvious that the cost would drop. But then back to the speed question, what premium is on the speed?... where does the requirement drive the design? Since Army owns the comanche data, surely they considered such options.