It depends on how much you wanna weigh at one time. I use a regular digital kitchen scale to weigh base grain out of my 50lb sacks. Only problem is it has a 6lb limit. So I have to weigh out my grain in 4lb batches. I stay away from the upper end in case it's less accurate up there.
I have tested the accuracy with my specialty grains that I bought and weighed at the homebrew store and it comes out the same every time. It's definitely not the most convenient but I had the thing in my kitchen already and it works (in a way) so I don't feel the need to buy a new one.