> Ring is a $300 purchase and takes an hour to install. This would take me a few weekends and would cost thousands of dollars. Cloud centralization makes things easier and cheaper, by orders of magnitude.
I have a number of "old school" network cameras and an on-site DVR, it doesn't take "a few weekends" to set everything up.
Adding a camera is simply a matter of following the instructions to connect it to the network. This would be the same process for a Ring or an "old school" camera. Adding a camera to Blue Iris is a 5-15 minute job, depending on how much tweaking you want to do to the motion detection settings.
In terms of implementing from scratch, I picked up a refurbished Windows 10 Pro machine, set up and updated Windows, installed Blue Iris, and added my cameras, in an evening.
Cost-wise, my setup is more expensive than a single Ring camera. However, my incremental costs are a lot cheaper since I can buy sub-$100 cameras instead of $300 ones. There's also no monthly fee, which is nice.