I think it's good to be frugal in some areas but not in all. Don't cut corners when it comes to the health and safety of your family (for example- if you need new brakes on your car- get new brakes). That doesn't mean you never eat a crappy meal because it is cheap but that shouldn't be the norm.

Also education for the kids. We homeschool our kids so whatever tools they need (devices, books, stuff for experiments, subscriptions etc) we don't think twice about. And each kid gets at least one extra curricular activity.