Ask HN: Would you review my startup idea?

Hey guys, I'm a senior in high school and I'm trying to launch a startup that I think would really take off. Of course, this is just me speculating and being blindly optimistic. I'd really love the HN community to check it out and give me some feedback, I'm prepared for both positive and negative! ~~ The idea would be to swap textbooks constantly. So with a large enough user base, you would always be able to search for a book you need for class and then just have it shipped to you ($2.00 fee + shipping/handling). And in return, you would put up all of your old textbooks to swap on the site. This way, you don't lose money because in the end, you're always swapping for all four years of college. ~~ Again, it's an idea I've had for a while and I made a sign-up site: http://lendsit.com

Thanks so much, I really appreciate it,

Alex