In general, yes - ten thousand AAdvantage miles are worth more than $50.

Good luck getting the card or the miles out of this offer, though. I applied a month ago, and haven't heard anything. I tried to call Citibank twice, but was placed on lengthy hold both times. At this point, I have no choice but to wait and see if any credit card shows up in my mailbox. I'm starting to feel pretty stupid for filling out that online application.