"My post which you gave the url to was specifically directed at how Oberg's comments supported mine in opposition to Larry's which you denied. I can't see how this reply is relevant to that post."

I get the feeling that you think that Oberg provided some sort of cost estimate of a manned Mars mission. If this is true, then you are mistaken. Oberg point was that Gregg Easterbrook and others didn't a basis for their claim that Bush was proposing a trillion dollar NASA program to go to Mars. If anything, Oberg was arguing against one of our points (and Zurbin's), that any conceivable manned Mars program which involved first going to the Moon would a repeat of SEI- a massive 500 billion NASA program- which was completely unrealistic NASA plan.

"I agree Bush's plan is very nebulous and leaves lots of room for interpretation."

I don't think it is nebulous. And if the yet to be appointed commission think there was a lot of room for interpretions, they will fail in their task.