That's a lot of cheaper robotic missions. If something breaks, there's another one in the works.
We should also be developing robots that can do what the human can do. That investment will pay off in many ways.
Btw, the first DARPA Grand Challenge was a bust in 2004. No one finished.
https://en.wikipedia.org/wiki/DARPA_Grand_Challenge#2004_Gra...
That investment is absolutely worthwhile, but we aren't even vaguely close to a general-purpose robot that can do what humans do. One human geologist could do the work of an entire fleet of Curiosity rovers. It's a matter of if all of the associated dangers of space travel worth all of that scientific knowledge gained from both sending people to do interplanetary science and from developing new tech to get us there is worth it - IMO, the answer is a resounding 'yes'.
I bet we can get the money for better robots. It doesn't even need to come from NASA's budget. The DoD, private industry tax breaks, etc can pay for the research.
https://www.wired.com/story/atlas-robot-does-backflips-now/
If we lose a robot on Mars, not much changes.
My observation is that we can start immediately with attainable goals, at a cost we'll likely accept, with no risk of human life, and with immediate economic and technological benefits.
In the meantime, we've lost 4 years... with another decade more with no real goal.
My suggestion makes forward progress every year. At some point, sending humans to Mars, for example, becomes a small inexpensive step, rather than a giant costly leap.
We've invested many billions of dollars on robots already and this is the best we have. If we could spend $200bn to do he science in a few years that trillions dollars in R&D and probably the better part of century of iteration would take, why wouldn't we send humans up?
It seems crazy to me to throw money at robotics that work well on Mars when we are already investing billions and billions of dollars on robots here on earth that aren't even able to do the things that humans do.
That's not a lower bound. That's an upper bound on what hopeful NASA contractors think they can milk the government for in doing it The NASA Way.