printing q

I have 35 network printers on my network. These printers are shared via Ip address (jetdirect). They are all connected to my print server/file server (win 2000 server). I have certain users that print 350 page documents on my laserjets, and I do not want them to do this. How can I limit these users to 50 pages per session with the least administrative effort? (boy that last part sounded like a question straight off of microsoft’s tests :))