Just for your info, I bought all titanium clad HP Elitebook for just over 240 Euro sometime ago at eBay. It is like one quarter of the original price.
I even did not have to auction it. I selected a professional seller with a good reputation in my own country and picked what I thought most compatible for my needs.
I am also running MXLinux on Raspberrry Pi4. You can pick up 8 GB model around 100 Euro. Mine is 4 GB model but it is fast enough for the basic computing needs.
The distro you can install on RPi4 is rather limited, but there will be absolutely no driver issue since the distro is optimized for the hardware.
You can create Retro gamebox using RasPi. Just for a few examples:
I have about a dozen of RasPi running in our household, working as connected speakers (Volumio), Pi-hole, Print server and Wordpress server.
Great thing about RasPi is that it is inexpensive (excluding maybe the high-end Rpi4) and I can be a bit more adventurous. After all, RasPi is created for young kids to learn computing. It got be quite durable in those clumsy small hands
Your machine seems to be most Linux unfriendly system I've ever seen.
I wonder if @Aravisian might have any other idea. I am completely out of idea at this point other than switching the system for older laptop or RaspberryPi.