That's how this works, right?
I chipped in $10 (as cool as some of the rewards are, they are clearly targeted at filthy billionaires who will be first against the wall when the revolution comes), and I expect that I will hear from J.J. Abrams very soon that, against all odds, I have won and will be in the new Star Wars movie! On the off chance I don't win, I really hope the guy who played Jar Jar Binks is contributing heavily—totally stacking the deck—and then when he wins, insisting on appearing in the film as Jar Jar. And nobody could get mad if this happened, because Unicef!
(General nerd discussion about this appears to be along the lines of "omg a puppet!" or "Is that a Toyota Tercel in the background?" or "omg a puppet!", but the bigger/actually important thing here is that this charity auction/rewards system is a pretty great idea that probably more blockbusters should start doing. And yes, omg puppet.)