The digital scales are what I prefer to use, but given the budget as stated by the OP, I would invest in a mechanical beam scale. They are slower and you can damage them, but they don’t just go bad or stop working on you if you take care of them. Had one digital scale that would just go out of adjustment at random times and couldn’t trust it. Personally I currently use both a mechanical beam and a digital scale. Easy and reassuring to make sure they always agree. One beam scale I have still works great even though it was made around 60 years ago by Herters. I also have an industrial lab grade Sartorius scale with certified calibration weights (bought it as a non-functioning item at going out if business sale for scrap value, only thing wrong was that the power cord/transformer was missing, but it was found in the box with the weights), but that is not what the OP asked about. I would recommend the best mechanical beam scale the budget allows, then buy a digital scale to pair with it when you can. We are talking about weighing gun powder here, correct?