There is no additional charge (other than park admission) for going to CP. If you don't have the dinner package you will have to wait in the stand-by line and it is first come first serve to the remaining seats. If you have the dinner package you are guaranteed seats, which are reserved in the front (covered) section of the theater. We find it easier to get the package just because...it is nice not to have to get there super early and wait in the "stand by line" and we have to eat anyway.
We think the package is worth it. There are different price tiers based on where you want to eat so there are options in that...the voucher covers a non-alcoholic drink, appetizer, entree and dessert...The seating is really worth it as well. It can get kinda crazy depending on who the narrator is for that night. If you are in the stand-by line you might not get in, or you might be in the standing room in the back of the theater. If you have the package they have reserved seating for you.