The grass is grown on a sod farm just for Boston College; this contract gives BC a good price break. Buildings and building spaces are much more expensive and require lots of planning and then ongoing maintenance. That said, I have heard that BC is looking very closely at existing spaces that would be suitable for practice, performance and collaborative study. I think the answer to your question is that BC can afford both grass and student spaces- we just need to see what their final plans are for student spaces.