Oooh… I hate questions about money. 🙁
But okay, I’ll give you an answer. The assumption here is that you’re new and starting from the bottom, which will most likely be the case, and that you’re having an average ship career. With that in mind…
The short answer would be: somewhere from around 800 to a thousand U.S. dollars per month, or more.
The longer answer would be: depends whether you work for a cruise line or a concessionaire, whether you’re a new hire or a manager, whether overall sales is doing well or poorly, what your individual sales performance is, which cruise line you’re with, which ship you’re on, and what the ship’s itinerary is.
Some itineraries are better than others. Some cruises are better than others. Some ships are better than others. Some cruise lines are better than others.
You get the idea. 😉
And, no, you most likely won’t have a choice as to where they’ll send you.
Now, before you start whining, remember that as crew member your board & lodging are free, you won’t be spending money/time on commuting to/from work, and you get to travel the world! 🙂