I have a friend looking to set up a game server, the problem is neither I nor him, have any idea what kind of bandwidth a game server will use.

He plans to host a room of 32 people. We estimated only 3-6 hours of the day, the server will have 32 people in it.

ANY estimates are highly appreciated.

A lot, nothing any home user can get. Unless of course we're talking about a remotely hosted one.

Will 500GB Cover it?

Probably.

I believe one person on here said each player equals about 5 - 10kB/s.

All depends on what game.