We bought a Barbie Power Wheels Jeep (or whatever it's called) at a yard sale a few months ago. They were asking $20, it was pretty worn. We asked them to start it up and they said the battery needed to be charged. We left our number and they called later to say that the battery wouldn't take a charge, but they'd let us have the jeep for $10--which they delivered! A quick trip to the neighborhood walmart where I bought a new battery for about $70 (it's cheaper on line).
It works like a champ, though there was quite a bit of wear & tear on the wheels, I'm sure it will last until cold weather arrives.
If I were going to pay close to $100, it would have to be in tip-top shape. If the one we bought had functioned with the original battery, I'd have thought $25-$30 was a steal.