I call it the Jack Shephard method, i.e., you either keep it really short, or don’t cut it at all.
Either method will save you both time and money. I usually go with short in the summer and let it grow more in the winter. I had a friend in high school who would shave his head for the city swimming finals in the winter and then let it grow until the next year’s finals. Yeah, he was in high school so he could get away with looking like a ragamuffin for 4-5 months, and he had a good skull for the totally bald look. But, if you can pull it off, think of how much extra time you’ll have if you only cut your hair once a year!