I have a tabletop scale that I mostly use to weigh salt when baking. It's some no name brand I bought at a head shop for $80 (i.e. overpaid.) It weighs up to 1000g and came with a 500g calibration weight. Even though it's made from plastic it somehow warped so now it doesn't always sit flat on the table and the buttons stick in the frame. It's not a nice unit by any means.
I haven't calibrated it since I got it 5 years ago. Every time I toss on a dollar it reads 1.0 and I just put the calibration weight on it and it read 500.0. I was impressed! I'd say there are cheap, reliable digital scales out there.