I just bought one of these with 4 wireless cameras for $14, without a hard drive because I had a spare from a dead computer:
https://www.amazon.com/gp/product/B07FSFXZZ3/ref=ppx_yo_dt_b_asin_title_o00__o00_s00?ie=UTF8&psc=1
It has everything you need. It works out of the box. The hardest part is deciding where to cut holes in your house to mount them. I am going to mount them on posts, myself.
The only concern I have is they are made in China (they all are), and I am sure they will be selling the feeds to the NSA. I intend to keep mine offline most of the time and just record to the hard drive.
If you search enough you can find them even cheaper.
I meant $145. That was a typo.