Define cheap. I'm running an Intel NUC d54250wyk (launched 2013) which takes up to 16GB DDR3L. You can't definitely find that class of hardware got cheap on eBay these days. Update SSD and memory and it's still great.

Stupid auto-correct. Should be: "You can definitely find that class of hardware for cheap on eBay these days."

Not sure which those are, but all the J/N 4000 series CPUs are only rated for 8 GB, yet I never heard of anyone having issues with 16, though not always at the maximum supported frequencies.

I have a 6th generation with 32GB:

    hw.model=Intel(R) Core(TM) i3-6100U CPU @ 2.30GHz
    hw.physmem=34227793920

Yeah it's a i10 NUC (not exactly super cheap), which takes 2x16 gb without problems. I'm running debian...