Well it's my last year in High School and I have become good friends with my Computer Science teacher, each year we get this mini-grant for $500 dollars, this year I get to spend it

. I need to figure out something to buy with it for a school related project. I was maybe thinking a decent computer for a main node for a cluster, robotics stuff, software, or??? Anyone have any suggestions on what to buy for a school related project?
Thanks