I make my autograph books out of a spiral bound index card "book". I simply flip it over so that the back is the cover and when you open it, the characters sign on the unlined page. I do decorate the cover with Disney stickers and my kids names, etc.
When I get home, the pages are perforated (sp) and I just separate them from the "spiral". I use a regular photo album and slip the autograph in next to the photo of my child and that character. Not sure it's any less expensive then buying one, but I have the satisfaction of know that I made it for them.