Bought a milligram weighting scale:
It came in a fancy box, with a 5 g and 10 g reference weight as well (the 5 g reference shows 4.999 g and the 10 g reference shows 9.995 g). Needs 2 AAA batteries. I think it is very good quality for the price, I can recommend it if you need such a scale:
http://cgi.ebay.de/132225160852
Does it allow you to use those weights to recalibrate the scale? Also what is it like at the corners rather than the centre? I have 2 scales which are an order of magnitude less sensitive. One of them is great no matter where your load is on its bed, the other gives +/- 2 counts predictably. I obtained the 2x 50g weights separately and used them to recal using the zero and 100g adjustments
The manual doesn't say anything about calibration. 10 g now shows 10.018 when the weight is in the center, and 10.022 when it is over the cylinder at the side which goes into the case. Should be no problem, because the plastic cover can be placed upside down in the center. But looks like +/-0.2% error, because last time it showed 9.995 g, maybe depending on temperature (it is a bit colder here now)? But tricky to measure. Before I cleaned the reference weight of fingerprints with a paper towel, it was 3 mg more, maybe I should use some solvent, and then not touching the weights with bare fingers.
The LED weight is the same, which means the error is relative. Still good for the price, I don't need it very accurate, but was just interested in weighting parts.