I had to lose weight before I could even think of trying to buy a scale that could give me a reliable weight.
I would go to my doctors office when I wanted to take my weight. Never needed a apointment or to see a doctor just to use the scale so I would just go in and aske to be buzzed in to go use the scale.
If you are below the normal weight restrictions that most scales have usually any that cost more then $25 dollars will be a good scale.
But maybe someone has a good one for a good tip.