The launch cost isn't low. They're using an Atlas V-541 from UAL. The program cost is equivalent to about 10% of NASA's annual budget, which is a lot. Mars and the rovers are just one corner of NASA's focus.
It would cost a minimum of another $2 billion to duplicate this rover and mission, if you can find enough qualified people to task to it so as to not harm (by dilution) your ability to deliver on at least one of them. NASA's resources and talent pool are both very much limited.
It would cost a minimum of another $2 billion to duplicate this rover and mission, if you can find enough qualified people to task to it so as to not harm (by dilution) your ability to deliver on at least one of them. NASA's resources and talent pool are both very much limited.