Me, I just buy cameras to use until something happens to them and then put them on the shelf. My justification is one day, I'll get them repaired and put back into service. Admittedly, some decades ago I had some 300 hundred cameras of which may 5 I used but then woke up and decided a couple of good systems was better for me than 300 cameras. Today, I have 4 users and about the same number waiting to go in for repair.