I just bought a RCBS M500 a couple months ago and am very happy with it. It's all metal and works like a charm. Current U.S. nickels weight EXACTLY 5 grams, which equates to 77.16 grains (77.2gr) and I've verified it's accuracy all the way up to 6 nickels (463.2gr).

Not much more you can ask from a scale and they're $68.