With that budget I'd recommend sticking with the classics like the HyperX Cloud Stinger 2 or similar models - they're robust and sound solid for the price. Though you should check first whether your friend prefers wired or wireless headsets, since that can affect the price. If he plays a lot of Discord, good microphone quality matters, so I'd go with a more established brand rather than budget ones, because then people can actually understand what he's saying. My tip: check out the reviews on Amazon or wherever, pay attention to comments from people who game a lot, and see if there are any well-known models on sale at the moment - sometimes you can get something better for your money that way.