How much Internet data does hosting a small minecraft server use?

I'm hosting just a small Bukkit server for about five friends. I'm on a satellite Internet plan so I need to know how much data it uses when it's up. If I were to leave it up 24/7 I'd say people would only be on it for 1-2 hours per day, if that helps.

If your the onlyone using the internet 50-100GB
If your family will use it you might need 200-unlimited.

It really depends if the server has a lot of mods installed to be downloaded by friends.
The average per user an hour
Sent: 1.4 MB
Received: 15.5 MB

x Times this with the number of people on and that's about how much data you will use up every hour.

So in your case we will use 5 people.

5 x 15.5 MB =
Data usage per hour would be around 77MB

It depends on the version of the game. A new version would use about 215 megabytes.