Tickets will probably be cheap, and maybe nothing, or they will be expensive for a fundraiser.
Chances are very high you'll be able to bring a second book to get signed of your choice, unless the signing is restricted to UtD only.
You'll definitley be able to get your picture taken with him, but the books might be pre-signed and you won't meet him at all.
The event will be at a bookstore, unless it's at some theater like Symphony Space or the Jacob Burns.