That's not how you should buy tools, though. Unless you're a professional who is making a living with these tools, you don't walk straight up to the Snap-On truck and drop several grand on all the highest quality stuff. You go to Hazard Fraught and get the cheap ones, then you replace the ones that actually wear out or don't cut the mustard with something a few tiers up. Most of it will work just fine for a decade at a twentieth of the price.
The crowd here could probably build one of these out of whatever's in the junk drawer. Looks like it's the RX half of a cheap analogue walkie-talkie and some flashing lights. That's it. Two hundred bucks is egregious. Maybe if you were an actual LEO or a private eye, but for most people it makes absolutely no sense to buy the $200 version without first seeing if the $10 version does the job.
Well this is certainly subjective and dependent on multiple factors. It may very well be that you could get a similar device for $10-$20 or scrap one together for as much, but its probably not going to come with a good warranty or much reassurance of it's actual performance. And also, just as the crowd here is more likely to be able to build one, the crowd here is also more likely to be able to drop $200 on something if they want it.
Use cases matter. Someone worried about voyeurs should think like voyeurs. They're driven by impulse and most of the time are probably not going to be super organized or resourceful. There's no need to waste your money on RF detectors or camera lens detectors if you are dealing with the kind of hidden surveillance equipment you'd see on Amazon; it's not that sneaky and you can just examine objects like clocks, smoke alarms, door hooks, and phone chargers for obvious cameras. These kind of surveillance devices are really only hidden to people who aren't looking for them.
OTOH if it matters enough to want a camera lens or RF detector I'd definitely at least want a good piece of tool. Doesn't have to be the one in the article, but it'd certainly be worth considering. This is especially true in cases of potential corporate espionage and other situations of similar importance.
Not at all saying there isn't a market for a cheaper device or a DIY replacement, but to be honest I think a lot of people are better off with buying nothing, if you ask me.
The crowd here could probably build one of these out of whatever's in the junk drawer. Looks like it's the RX half of a cheap analogue walkie-talkie and some flashing lights. That's it. Two hundred bucks is egregious. Maybe if you were an actual LEO or a private eye, but for most people it makes absolutely no sense to buy the $200 version without first seeing if the $10 version does the job.