Devil you know vs the devil you don't. How is it living with your parents? Is it worth several hundred dollars a month to be away from them?
You've never lived with this friend, so you don't know how he is at home. Will he have women over all the time, making various noises you'd rather not hear? Closet drug addict? Does he tend to leave underwear in the kitchen sink?
I've had different roommates throughout college, and I'd finally had enough of the social living scene. I've got a decent apartment by myself now, a few miles from campus. It is about $75 more per month than on campus, though it varies depending on my utility bills, but it is so very much worth it. No loud neighbors, no month-old piles of dishes festering in the kitchen sink, the stove is not encrusted with a grotesque assortment of oils and crispy food, there is plenty of space in the refrigerator, I can operate on my own schedule, and my car is parked about 5 feet from the front door. (With campus parking, it was anywhere from about 150 to 750 feet away, very approximately.)
I wish I'd lived off campus from the start, but at least it gave me some perspective on just how good it is to live alone. Damn freshman go totally nuts once they're away from mommy and daddy for the first time. Respect for neighbors? Hah, it doesn't exist. It's more like a bunch of orangutans in a competition for dominance, accomplished by seeing who can make the most noise, or drink the most alcohol without needing a stomach pump. (First semester, someone in my dorm was hospitalized for alcohol poisoning. Brilliant people.)