It depends on the light.
Most of my lights have been in the 100-300 USD range.
My favorite is the Muyshondt Aeon - Neutral Tint Titanium. It's a pricey light, but I have forgotten what it cost me, from memory around 300 USD shipped to my door.
To be honest though, I don't care what it cost me, if I lost it I would be trying to find another straight away.
its a small, bright, stupidly simple, amazingly machined custom flashlight, and I have carried it every day since it arrived.
My Maxabeam is the most expensive I have bought - about $800 shipped to my door - for what the light is and does I feel it's well worth the money (so much so that there is a second one on its way to me along with a spare bulb, long power lead and hard case)
spending a good chunk of change on quality tools means you will look after them, and that they should be able to stand up to some abuse if and when you need it.
medics, firefighters, cops and security guards can be hard on their gear - cheap gear that won't hold up is a waste of money, and more expensive in the long run (because you buy it, then have to replace it with the item you should have bought in the first place)