Bicycles
If you can get a bike at a decent price, maybe you should not worry that much about buying a used bike, even if it’s from someone you don’t know. But if the used bike does not exactly come cheap, you might want to give it a little more thought as it can come with various downsides.
A bike’s value is determined by its frame, as well as its wheels, gear shifters and their quality. If you can’t really tell if those parts are high-quality or not or if other parts have not suffered any damages, you should probably consider buying your bike from a certified seller.
Related: 8 Things It’s Smarter (and More Profitable) To Rent Than To Buy