The trick would be to figure out how to get them to use the chin strap. Kids usually wear their helmets, it's just that they do it in such a way that they are completely useless.
In our expensive area of California, I rent a 10-year-old granny unit for $950 a month. My fiance pays $2650 a month on an interest-only mortgage for a 30-year-old ranch house that is only slightly larger. My commute is three miles, his is 16. My neighborhood is much nicer and has better access to stores and cultural amenities. I have no maintenance responsibilities, and my utility bills are much lower. Of course renting is better!