The key thing here is to know what you're getting, and to make sure you have the appropriate port free (or that you have Bluetooth support). If you opt for a cabled mouse, don't forget to check the cable length. Is it long enough to reach from a PC tower on the floor to your desk? Is it six feet long, but only needs to run from your mouse pad to the laptop beside it? Also look at the cable itself. A braided nylon or cloth cover is more durable than a standard rubber coating.
When buying a gaming notebook, get one that will last you for a few years. If you can afford it, get at least an Nvidia GeForce GTX 1060 for basic VR support. That choice is more important than RAM and the CPU, though you should pay attention to those as well. Storage is the most likely to be upgradeable, but more is better, as games take up a lot of space. Decide if you prefer high resolutions or faster displays and consider what software will be helpful to you, but realize that you won’t get great battery life. How all of those work together determines just how well a gaming notebook does on the Tom’s Hardware test bench.
Gaming laptops can put a serious dent in your wallet, with some of the fancier models costing upward of $3,000. But who says that the right rig has to cost an arm, a leg and the soul of your firstborn? Fortunately for the fiscally conscious gamer, there are some sub-$1,000 notebooks that can run graphically taxing games like Destiny 2 and Shadow of the Tomb Raider at solid frame rates.