As you correctly say, more accuracy costs more money, as does a display that displays more/longer numbers!I have two different multimeters, both function well but would be relatively cheap.e.g 10 to 20 euro price range. The minimum accuracy quoted is the same for both on the voltage scale, which is (+/- .5%) + 1digit (least significant digit) I think this figure is typical on budget multimeters.
So reading on the 200V scale, at 42volts, the tolerance would be .21v +.1 =.31volts. i.e An error of (point3) or .3 volt or even possibly .4v would be within the tolerances or put another way, a reading 41.7 - 42.3 or possibly 41.6-42.4, would be within the quoted tolerance.
More accurate meters are generally more expensive.
And I am sure that we both agree that cheap meters can still be a very useful tool for when working on an e-bike...
Very high accuracy is seldom, if ever, needed!
Especially if someone takes the trouble to compare to a known good accurate meter, and to note the difference as a percentage, the cheap meter is then more accurate enough!
Regards and many thanks for posting.