You usually pay in person, because different things cost different amounts. For example: a purchased autographed photo could be one price, bring an item to be autographed could be another price, having your picture taken could be an additional fee, etc. For the SS cast, I had special fan package ticket that covered the cost of one autograph per castmember, so I don't remember what their individual prices were, but with Steve, his autograph on my DST package was $40, and the photo was an additional $10.