i would recommend in installing cameras without a DVR unless you are willing to sit there and monitor a screen all day. many modern dvrs can send a jpeg to a mobile phone if motion is detected on any of the cameras. if you have a camera inside your home and your system sends an image to your phone..you have enough information to be able to contact the police.
depending where you are, you should be able to have a basic system installed for under $3000 which would include 4 cameras and a dvr.
do you use conduit in your installations. we always struggle with securing the cabling and the added cost of running conduit in a competitive bid situation.
yeah as the previous poster said:
Use copper-braided RG59.
You can power the cameras at a wall socket (provided you have a small power supply for each camera) at either end of the gym.
the cameras could be viewed on a single monitor using a quad splitter or through a DVR-which can record the video. the difference is cost
you would not get to good quality for $75, but depending on the application (do you simply want a clear image of whats going on?) then a decent indoor dome camera with a fixed lense should suffice.
this is a common problem with illuminators. we have used multiple illuminators that create a scatter effect and tend to diminish the flashlight effect that you speak of