I use the same one as Bassman and really like it, got mine at Bed Bath and Beyond with a 20% off coupon that seems to come in the mail monthly. The issue is with weighing small quantites, like 1/4 tsp almost all of the consumer scales will round off to 1, 2, or 5 grams. A 1/4 tsp of mace will be under 1/2 a gram so you could easilly double the amount you need. I found that I use the above scale for most items and switch to the following for very small itmes.
Harbor freight has a small (drug dealer) scale that weighs in 0.1g for $11 on their web site and in the stores. I can not link to the scale as it seams Harborfreight.com is down right now, but you can search for it when the site comes back up.
When my first scale I got off ebay died on me I think it was Pops that recommended RIGHTONSCALES.COM Try googling them. They have a variety of scales to choose from. I opted for the My Weigh ibalance 500. Adam was the gentleman that I talked to.
Thanks for all the help guys. Old poi dog it looks like I'll be getting the i500. Just over a pound of capacity and weighs by.01grm. And they state that you need a 500grm mass to calibrate. Already have that covered. I use 500grm weights to calibrate scales at work and have one in my toolbox!