The really cheap NVGs are Gen 1 and are made in Russia or China and some of them emit unsafe levels of radiation. Be careful about what you buy. Also, they require batteries, so in any EOTWAWKI scenario, they will only be useful until battery supplies are exhausted.
If anyone is serious about buying NVGs, get Gen 3 or 4. Expensive, but well worth it.
Spending 3-4 grand isn’t in my budget. I figure something is better than nothing, but I would need to do some research before buying. My thought is when your low tech alarm system (dog, tin cans on a string, etc.) goes off you can check it out without giving yourself away.
I have other things on my list that are more important than spending thousands of dollars on nvg. But, I guess it’s a matter of how much disposable $$ you have.