Printer Quotas in Linux?

borgquite asks: "At the school that I work for students waste a lot of paper and toner because they print without thinking. I've been looking at printer quota / charging software, but unfortunately I can't seem to find any for Linux, and the Windows based software is all priced far too high. What I need to do is to say that students can print a certain amount per day/week/month/year, and provide a system where they can pay to increase their quota. I've looked for Linux / BSD based solutions, but all I could find is lots of references to a tool called lpquota, but no information on how I can obtain and implement this on my network. Does anyone know of such a system?"