The cameras I've built have been in the $130 range. They are 3.2 MP white flash cameras. The cost will change depending on what camera you use and what features you want. For example it will cost more to build a IR camera than it does to build a white flash camera. Also you can save some money if you are able to get a good deal on the camera. Recently I was able to pick up one of the cameras I use at a rummage sale for $5. I will be able to build a unit for about $85 using that camera.