[milesvp]

I can appreciate if this is too much money for you, but I recently bought a 2014 macmini i7 16GB and 512SSD on ebay for $440 shipped to my door. I needed something that could handle bigsur for some app development, and that was the best $/effort solution I found. Add another ~60 for a usb switch and cables, and I can easily switch between my primary and mac.

In general, there's a pretty good second hand market for macminis, and if you shop around you can probably get something usable for under $350 shipped.