30/40 year old entrepreneur is more likely to be married or in a stable relationship; fun is Netflix ($5 a month) or streaming movies (free). Use wife's health insurance. $400 a month on transportation, really? Anyone with a wife/gf knows they don't travel that much anymore. No reason for utilities to be higher either. Food is way lower, older people are more likely to cook their own and make smarter supermarket choices. Being older and boring is very cheap.
If working from home eg programming, having your own place can mean that you sleep better and are more focused on doing the work, rather than being distracted by whose turn it is to do the dishes or joining in your roommates' post-bar parties.
Of course, having kids or being a caregiver would change the person's profile, regardless of age. Just a few counter-thoughts.