I went to undergrad oos and ended up staying in the city for 10 years after graduation. I got married and have now moved to another state, still not my home state. You just never know. Yeah, my parents paid for my housing in undergrad, and so it didn't matter that I moved to a pretty expensive city, but for those 10 years, I definitely wished I had been in a cheaper area... but my wife couldn't easily find work in her field just any where. Keep in mind life events happen, and money will majorly matter at some point.
Also (not to be Debbie Downer), your parents' financial situation could change. My friends parents lost one income while she was in grad school and all of the sudden, she was taking out loans and paying for living expenses when that hadn't been the plan. It definitely set her back significantly and she almost left school to move back home due to personal and financial stress due to the situation.