If the price tag is seriously low, and it’s not Black Friday or a sale, then most cheap sunglasses are not going to do a good job of protecting your eyes. To clarify, the price tag has no effect itself (obviously) but reflects the quality of the sunglasses. UV-blocking technology is where you come into a higher price tag, and if it’s good quality, then you’re going to see a higher price tag.
Your eyes are incredibly important so you definitely want to avoid sunglasses that are cheap and poorly made using inferior materials. The best men's sunglasses are made using high-quality materials and they are stringently tested. In the end, you really do get what you pay for.