It was mentioned earlier in here, but eBay. You usually can find them between 1-2 hundred. Or a different idea is to buy an entire H and part it out. Sell the drone and the camera separately and you will be close to whole and the ST16 will be nearly free plus you get an additional battery and props. I did this a couple times and ended up with two H's and three ST16s all for the cost of one full unit.