I have two scales. One is high capacity (30 lbs) for grains and the other more precise for hops etc with a 1/10 gram resolution. A grain scale need not bee all that precise as a few ounces one way or the other makes little difference. It's a different story for hops and maybe chemicals at times. The Escali scales are very popular and reasonably priced. Keep in mind that the fine resolution specs for the higher capacity scales can be deceptive. Often those are not sensitive enough at the low end where you may want to measure only a fraction of an ounce.
Here's a good source:
http://www.oldwillknottscales.com/
and another:
http://www.americanweigh.com/
Between those two sites you will find a huge selection of reasonably priced scales.