Using Hacked Wiimotes As Scientific Sensors
garg0yle writes "Scientists are repurposing Wiimotes as scientific sensors to help measure wind speed or evaporation from lakes, among other things. At about $40 per unit, the controller is much cheaper than specialized sensors. The scientists are still considering how to add storage and extend the battery life."
However, you're underestimating the cost of time. Mass production decreases both the cost and time of making a specific product (or combination of products).