Best Mini PC for Liberelec under 100€

From memory LE should run well with a discrete Intel card like Arc A380 if you want to retain your existing hardware. But I suspect a RPi5 would provide a comparable experience for far less power consumption.

I've got a RPi5 as a secondary setup and I can't notice any difference with my J4105 based HTPC in the lounge. I've got the RPi5 booting off a NVMe drive and it's a slick experience.