[kabdib]

Cameras are crazy cheap, less than a buck. Lenses may be expensive to design, but you might find something off the shelf to do what you need.

The expensive pieces probably go, in rough order: Case and mounting hardware, radio, reasonable quality sensors, embedded processor and support chips, power supply. Don't know where the cameras fit into that, since you want a bunch of them.

If you can't get a COGS under $200 you don't deserve to be in business.