That is a long list and depends on the kind of work you're doing.
For me, if I might need it, I have two; and, if I usually need it, at least six. For example, I have two of each double pole breaker up to 40 amps, and six of each 15 amp. Driving for parts wastes too much time.
With my current employer, I built the stock up over two years, so it wasn't a big expense at one time.
