I agree. I've used a lot of heart monitors over the years. Some can transmit data to a computer (through a connection with the watch/receiver) to be used for tracking one's stats. Those models are pretty pricey, I doubt a school would want parents to purchase them. Unless there was some guidance from the school on which model to purchase or what functionality was required, they probably should just get the cheapest model on the market. It doesn't look like they are trying to pull a Gatica-esque stunt here.
A simple heart monitor setup is comprised of the chest strap and watch/receiver and can be had for well under $60. IMHO, it's a great idea to get kids familiar with these things. They are probably the single best tool for making one's exercise as effective as it can be without over-exerting.