I have the MTM scale. I literally could not get it to settle on specific values (even trickling one granule of powder at at time), such that it would jump from 4.9 to 5.1, or 24.9 to 25.1.
I called the company. They said it's in the algorithm that takes the data from the device and calculated the displayed weight. It wasn't fixable, it was the nature of the device.
I, too, looked for cheaper digital scales. I read every review I could find, and most scales seemed to have at least a sizable minority who were unhappy with them.
Eventually, I closed my eyes, bit the bullet, and ordered the Dillon D-Terminator, since the reviews I found for it were almost uniformly complimentary. Yeah, pricey, but in the end, if you're not confident in your weights, it's darned hard to isolate problems (I shoot test loads through a chrono).
It would take two large men with crowbars to pry that scale out of my hands. I've found it to be stunningly good. No, it's not less than $50, but I now have great confidence in my results.