Video editing software for windows is terribly expensive. Things like the mentioned Final Cut is quite inexpensive for the abilities it has. Similarly compare the megabucks for a adobe photoshop license to the 99 US$ for a aperture license. Similarly compare MSFT's office to iwork.
The perceived cost of the mac will quickly fade once they look at getting legally licensed on the software side. Esp. when the schools get some decent discounts in place due to the volume they'll buy, it'll make very much sense to step away from Microsoft's offering.