Schools almost always have cheap systems. Schools run on tax payers' money so unless you feel like paying extra in taxes (or making a donation), don't count on schools being able to run 3D games. Most stuff in schools that I've seen is only designed for simple 2D educational games, office-related stuff (like word processing, student attendance management, databases, and spreadsheets), or simple 2D graphical art. There are a few exceptions, but these are quite rare cases. You could get a Radeon 7000 (or the equivelent Nvidia card) for under $20. Taking $20 and multiplying it by 30 for a whole computer room and you get $600.