Basic users don't even have to pay, and if you're doing something that requires the paid version you can buy and will benefit from the $300 control surface that also includes a Studio license.
The license isn't expensive for what you get. I bought the USB dongles so I can easily transfer it between computers and also completely block Resolve from accessing the network via Little Snitch.
I can also heartily endorse the Speed Deck control surface, which is way less than $300 and also comes with a pro license.
When I come across files that DaVinci Resolve won’t open, I convert them to a format that DaVinci Resolve likes by first using the open source command-line utility ffmpeg.