There's a guide to making a homemade microgram scale in the PD NBOMe thread (it was stickied at one point). You could do this and just remember that 1mg=1000mcg.
^
Indeed, no 0.001g scale will accurately distinguish between 2mg and 3mg. For that you would need a microgram scale (very expensive!)
I picked up a tanita 1210N at a very good price a while ago and it's been extremely reliable. The readability is 0.002g but I would trust the readout 10x over any cheap 0.001g scale. For anything below 10mg or so I can just weigh out a small amount and use liquid measurement to do the rest
I don't understand your response in relation to the question... Are you saying you have used and trust this model? Or just that it's cheapest among the scales that have been released most recently?