Super Duper Sky,
Well, you're right, you DON'T have to give up the other spot/seat (if you have more than one reserved), but you better have some money to do so. Usually the second deposite is MUCH more than the first one. It's usually any where around $1000-$2000 or more and it's NON-REFUNDABLE!! Unless you like to waste your money, of course you don't have to drop one of the seats that you are currently holding until the end. 😎