In general, legitimately Apple-approved Lightning cables don't sell for less than $ 8, and there are some that cost less than $ 10. If you are buying an item for less than the price, even if it says they are genuine Lightning cables, then you need to make sure no corners were cut when creating it, and you are assuming a higher probability of failure that is not (totally) your fault.
Rather, most of the time, corrosion and stress are the fault of the user. You can pull a cable out on both sides or let it come into contact with fluids, very few cables will withstand this type of use. You can also buy MagSafe Apple cables via online sources.
Here's what you can do to make sure your cables run smoothly:
(1) Take the hard plastic cover, only the cover made of hard plastic, while connecting and disconnecting the Lightning connector.
Apple claimed that its Lightning connector is more robust compared to the 30-pin dock connector it replaced. In fact, the Lightning connector is certainly more durable, having tested numerous cables. Holding the sturdy plastic sleeve while plugging or unplugging it with the Lightning connector will significantly reduce the risk of cable failure.
(2) Do not force or bend the cables.
Lightning cables are generally covered with soft plastic (rarely covered with flexible fabric), however, whatever their outer appearance, they are made of tiny cables that could break, and invisibly.
If you stretch a cable to its length and then pull it, then put some sharp bends in the middle and then tie it, you might notice what appears to be stretchy flexible rubber on the outside, but the metal inside is about to explode.