It could be realistic, emphasis on “could.” There are so many factors…
How much do your kids eat?
Would you paying for a cellphone plan, wifi, cable, netflix, etc?
Would you pay for their fun and entertainment?
What about clothing, toiletries, etc?
What about textbooks?
For some people it could be cheaper to have their kids live at home and commute. For some it might cost more and for others, it may make no difference. The people I know who lived at home during college and commuted, paid for most of their extras (clothes, entertainment, etc) with a job, so their parents weren’t paying for much if anything. Of course, this was back in the day…