Cruise ship onboard cost?

Great response from Tinkertoy,the only thing I can add is regarding the internet [seeing as most young people these days cannot get by without their daily internet fix]It is not cheap & it is humongously slow,it is satalite internet & often takes an hour to send a 5 minute email,so be aware.I have done heaps of cruises & the computers on board are one of the biggest dissapointments.Visit the pursers desk after a couple of days to get a print out of your spending todate,we often find young people get a big shock when they get their final bill [because you only produce your cabin key to spend on board],I have known of many who spend more on board than the cost of the cruise,so just be aware..Happy cruising,hope you have a great time..