Best place would be Trier. Much cheaper and lovely place. Lux is grand, but expensive against all out lying areas. and no offence, but metz is horrible, as well as thionville and longwy, unless you like being invaded by family cars filling with monthly shopping!.
For a 3 bedroomed house in lux, looking at 1500 or so.
For a 3 bedroomed apartment in Lux centre, looking at 2000
good luck.