In my case, like with everything else, "you get what you pay for". I wanted an accurate tough scale because I did weigh daily and wanted the scale to be a valuable tool in my weight loss.
I bought a "Salter" digital scale 8 years ago from a department store for about $100 Canadian. It has been accurate (with setting before you weigh, like silverbirch
said) for all of the time I've had it and requires the battery changed about every 3 years (I don't weigh daily any more). It's metal and plastic but we keep it in the bathroom vanity (tiny floor space and awkward otherwise) so it hasn't got a speck of rust on it.
It's got a big display and allows you to weigh in lbs. or kgs.