i see it as a way of taking a picture that you can then go show the customer "see, im not trying to sell you an engine for no reason"
AND as a way to be absolutely certain you are diagnosing 100% correctly so you don't cost yourself money being wrong
and it REALLY pays for itself when you can skip taking half the car apart to find tricky leaks. i just used it last month to find a coolant leak on a 2004 volvo twin turbo straight 6. after taking half the car apart to even be able to stick the cable of the videoscope up under the exhaust manifold and find a hairline crack in the engine block.
it depends on the volume of work and what kind of work you do.
so if you're not using it as a pro then it will probably sit on a shelf for years until you remember you have it and use it for an odd job, for that reason its better to get a cheap one, there are cheap video scopes available at home depot i've seen a few times.
said volvo, worst nightmare of my life: