Paul Strut

Hello, Last year I went in my first cruise ever, a Mediterranean cruise on Brilliance and I paid the full amount of the cruise and have no info about deposits and how they work. So, for example, I want to book a cruise for next year in September that is now 909 Euros and I have to pay a deposit of 500 euros. If the cruise gets expensive or cheaper in the meantime, I have to pay the remaining balance from the 909 euros or the price of the cruise in the day -500 euros. I`m asking because I know for the Alcoholic Package if you buy it and if the price gets down, you can refund it and get it cheaper. Thank you guys!