Why is university so expensive...

I just paid my housing application fee for my university(which was $154.50 it's self) and calculated my costs for everything and its over $8000 per semester. And thats WITH in-state tuition. I'm already getting the max for FAFSA and, despite already graduating, am still trying to get my SSN into my school's database so that I can try and see how much I can get with state aid. On top of all that, my mom's saying that I shouldn't work during my first year so I could get used to everything. I mean, it makes a little sense but I might try and have a little bit of my own income so I at least don't have to asker for money for simple wants. But why cant we just have more affordable higher education bro. This sucks. :{