3. going straight from high school into college
costs:
benefits:

The costs, other than tuition which you could argue would be a wash, would be experience and maturity. Many kids who go off to college are not emotionally, psychologically, or academically prepared for what is required. With the cost of tuition, a student could "waste" some of that if they don't know what major they want to pursue.

The benefits, at least for some students, would be that they don't have to find a job and support themselves. For those that are prepared, getting started and getting finished sooner make a lot of sense.