Hey look Hans, it all depends on what it's worth to you.
I've been to a couple of meet and greets over the years (although not at $830!) and it has amounted to about 10 seconds posing in front of a camera, shaking hands and a free book and drink with 50-100 of others from the audience. Not saying I didn't enjoy it, I did, that's why I did it more than once
Buzz's opinions on Mars are no big secret, he was a guest on this year's BBC Stargazing Live where he aired them. He seems like quite an interesting bloke to me.