I don't know of any public school with turf paid for by the school system. That is not likely to happen. Our indoor practice facility was paid for by boosters (close to $1 mil). Our field house was paid for by boosters. The new visitors stands were paid for by the school system. Of course...when we did that...Gordonsville got them also. They did need new bleachers because their homeside was condemned. They also got an indoor baseball/softball facility.
When you are winning especially...it is beneficial to expand. A lot of SC fans used to stay at home when they played at the U because there is no place to sit. The expansion there would pay for itself.