I was watching it in the mid to late 2000s
It was a dvd, and it was in a case with 3 other films, 1 being Gulliver's travels. Might have been 2 disks, or it might have been 4.
It was about a group of school boys trying to stop a diamond heist. The diamonds were hidden inside a girl's teddy bear
I can remember 1 conversation from it: "500 big ones" "You waste my time for 500 bucks? I can make that sort of money in an hour" "Who said anything about hundreds, I'm talking thousands, maybe millions". They are sitting in some auditorium, I think.
It may have been American, from the bus and school hall I vaguely remember. I think one of the kids sees one of the bad guys in the bus or something, which may have inspired them to set up base where they did.
I have tried imdb and "find my movie" to no success

Thanks in advance

Watching films are really useful sometimes. I even read this before watching your film so I could mention it in my paper.