look for a digital precision scale which measures weights from preferably 0.01 to 300-500 g, cheaper models will only have one decimal so you can also look at models that weigh from 0.1g.
Prices vary a lot but you often get what you pay for, in the price range of 40-200 USD you should find something good. Some good ones might be even less.
I use a precision scale from KERN that cost me around 120€
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