I've been doing some research and it seems for ~$2000 you can get a decent camera that sees ~2000ft, or for ~$500 one that sees ~500ft. I am looking at these mostly for detection of animals in/close to the road at night as I tend to do a lot of non-highway driving at night. On a night I go to visit my girl (1 hour drive) i usually encounter 15-20 deer on a standard summer night. Most of the PSL are under 45 so i think 500ft would be sufficient as usually once the brakes are hit the deer tend to scatter (they jump back and forth sometimes not sure which direction to go so it takes them a while to clear the road, so if you are too close to them when you start to brake you could be in trouble).
That being said, I dont mind putting in a good handful of hours if it can save me ~$200. Has anyone ever built one of these, or know of somewhere I could find one cheaper? Im no stranger to technology and I dont mind taking the time to research and learn (thats basically all I do anyway as I am still in school) but I thought I would ask here before I dove in.