I'm doing a project that requires me to attach 24 different wireless accelerometers to 24 different people, get unique acceleration data from each, and I need to keep the cost of each wireless sensor to below $50 a pop. I have seen a bunch of good options such as the WiTilt at Sparkfun, but the cost is too high. I also looked into rigging an Arduino with a Bluetooth shield and accelerometer, but again, the cost is a little too high. The best option I have seen so far was buying a bunch of nike+ sensors, which are cheap, but they only give impact data, not acceleration or motion.
Does anyone know a good option for doing this?