You might also want to try home stores like Bed Bath and Beyond or similar stores. Sears might also have some.
I know there are digital scales that are not kitchen ones (ones you weigh yourself on). They might be a bit cheaper and would still give you what you are looking from.
AI have a digital food scale that I purchased at Bed Bath and Beyond. It's made by Oxo. I did buy it for kitchen use, but it might also work well for weighing kits. BBB has other brands, in a range of prices, that would probably work equally well. If you are on the mailing list for BBB, you could use one of those 20% off coupons they're constantly sending out.
Although there are digital scales for weighing people, and they are sometimes less expensive than a food-specific scale, they generally don't register the tiny weights you would need.
Target and Walmart do carry a few models of scales, but I find that if I have a coupon from BBB, I can get a nicer product at equal or lower price.
i bought a digital/electronic scale from frys,/which is a huge local electronic store($100.)maximum weight 25#,./.reads #,oz,kg,grams great for kittens,rabbits,foods,use the phone book,..sincerely james waller