I would argue living below your means is always better. Getting a cheap mortgage you can add an extra $100 or $200 a month to for the first five years makes a TREMENDOUS difference in how much interest you pay over the life of the mortgage and how soon you own it. The first five years of a mortgage are so important, all your payments go to interest. I’ve turned all my 30 mortgages into 15-20 year mortgages by over payments and it’s served me extremely well.
May or may not be an option for you but buy any camera that supports rtsp, only allow that traffic from their network through and block everything else. Works fine for me and my Amcrest cameras. You could accomplish this with a pi and a USB network card and some basic iptables.