Less expensive is not the same as more efficient. Efficiency is measured by output per dollar not dollars alone. You got one more efficient versus 2 less expensive, and I don't see how Golembeck squares 10 man-minutes of work out of Sojourner with being more efficient. I ran the numbers based on that and a manned mission would be a far better return on investment on a $/man-hour worth of work basis based on 1 100 billion 500 day stay on Mars. Spread the heavy lift development costs over 10 missions and it's way better. Of course now you don't even have to include them becuase those are being spent on going back to the Moon.

Of course Squyres would change his tune when he thought it was unrealistic to expect the money to be commited versus it has been commited if getting the money was his only issue. I'm not sure when the comments I heard him make in documentaries were recorded, but he clearly stated humans had capabilities far beyond the rovers. It doesn't take a rocket scientist to figure that out. If robotic automation was superior to human flexibility, creativity and innovation we'd all be out of a job. Scientific research at it's best is highly innovative, creative, and flexible. Space probes are superb tools and without a doubt the best way to survey space, but boots on the ground will be far better ways to answer the questions we still have after multiple space probes. It should be obvious they are still unanswered because space probes are not good at answering them.