Generally baking scales arent over accurate for small quanties if you get the cheapest on the market. it should mention on it what weights it can accom
Small scales are called percision scales. they measure in 0.001 to a mid range weight.
They are generally used for science, jewerelly, drugs which makes them readily available if you are in a big enough town find a shop that sells drug paraphernalia and you should be able to pick one up for 10 to 20 euro