You get what you pay for, and goggles are no exception. There is a chasm in quality between a cheap set of goggles from a no-name brand and something from a well-known optical company. More expensive goggles will feature interchangeable lenses and straps, higher quality foam, and venting, and the lenses themselves may also have hydrophobic coatings and contrast-improving tints.
With that said, goggles take lots of abuse and lenses are going to get scratched, so it's important to weigh the above against the price.