Room pricing works like this:
you have your room catagories - inside,ocean view, balcony, and suite (many cruiselines also have in between sizes too - Royal caribbean has an inside catagory called a Promenade room that only sleeps 2 I believe but has windows overlooking the Royal Promenade and then there's also a junior suite or mini-suite on most cruiselines)
each cost more $$ as you go from inside to the highest catagory of suite.
prices are per person so for example if an balcony room rate is
$800.00 than it would cost $800.00 per person making the cost for 2 people $1600.00
If you get a triple or quad room it is usually say $800.00 per person for the first 2 guests in the room and then the 3rd (or 3rd and 4th ) person are usually slightly less -- say $500.00 per person making the fare for 4 people $2600.00
These numbers are totally pulled out of nowhere and I'm just using them as an example so you'd need to actually price them out.
Suites can cost $3000.00 or more per person so yes you were correct.
If you're looking at Royal Caribbean they have a family stateroom on many of their ships in an interior and ocean view catagory but you need to reserve through a travel agent or by calling - you cannot book it online.
That may be your best option