The problem with security cameras is that insurance demands them, but does not state a minimum quality. Which is stupid, but obviously they see more profit in security being a theater instead of real stuff to prevent incidents.

So if your contract just demands video cameras at every corner and X days of retaining the video, how much would you invest into high-quality, high-definition cameras and quality-retaining video storage?

You can actually buy "outdoor security cameras" for $10 a piece - or you can buy professional stuff for $500 or more. You can store hours after hours of video footage of 16 cameras on one old, worn-out video tape, or invest tens of thousands in disk arrays to store high-resolution video streams. Guess what businesses do when the only requirement is to "have a video surveillance system".