Wow, that’s very low. I made a live usb of MX XFCE and one of Fluxbox. Running off the usb XFCE was using around 675mb and Fluxbox seeing 450. I then also tried Linux Mint Cinnamon and it was running at 745mb idle.
Fluxbox was a like too bare bones for me, XFCE was nice but Cinnamon is even nicer so for just an extra 200mb I went with Cinnamon. It’s using less than half of what Ubuntu does and gives me everything I need.
But I think I’ll run MX in a KVM VM just to use it, get used to it and see whether I might prefer it long term. I like that it uses less systemd.