I have some insight on this....
I have a 4 camera setup, with included DVR. About $250 for the setup. No monthly fee.
Always on, records to its own internal hard drive.
Beyond 15 feet, I can't even recognize my own kids.
Motion detection and alerts is useless, unless youa re actively looking at the screen and can just chase the miscreants off.
But you also get 6 hours of a spider spinning her web. Literally:
And the wiring is a hassle. But don't succumb to the "WiFi security camera" fad.
Bottom line....you can get one.
But don't expect NCIS level camera clarity for cheap.
For instance, this is similar, and cheaper, than the one I have:
https
/www.amazon.com/FREDI-Security-8-Channel-Outdoor-Weatherproof/dp/B06W9FFY6K
Be very, very, very careful if you decide to port forward and access it from outside the house.
Many of these have abysmal security protocols. Built in backdoors, default admin passwords, etc, etc.