room service on Princess Cruises - fee, or not?

Greetings! My wife and I went out to a nice supper and movie last
night, followed by a couple of episodes of "The Love Boat" when we got
home (1 episode had my wife's favorite - Charro - to her delight) Man,
that brings back memories - I used to watch this show as a kid, along
with Fantasy Island sometimes. The show holds up particularly well,
with a fantastic guest list, good writing, and a theme song that makes
me want to look up the singer to see if he has any CD's available.

Anyway..... it got us thinking about our upcoming week long cruise
on the Caribbean Princess. (now just 28 days away!)

I come from a pretty frugal family, so I was wondering what might be
included on the cruise that I would normally shun? For example, I
thought I read somewhere that room service is included, but I find
rather vague info online when I try to get more details:

"If you order room service, there might be a fee during some hours on
some ships, and the menu is often limited, and all of that will be
outlined in the information folder in your cabin. Also, if you order
room service, please hand a cash tip to the person who brings the food
to you! The custom is $2 for the first person having food delivered, and
an extra $1 or $2 for each additional person getting room service."

I think I would be really tempted to enjoy room service for the first
time in my life, if I knew for certain that there was no fee involved,
other than the tip. Can any of you who have actually been on the
Caribbean Princess shed any light on this for me please? Danke!