See a psychiatrist. Not because you cant seem to muster the intelligence to buy an alarm clock, or because of the fact that you dont get up eariler, by setting your alarm to go off earlier, but because you actually asked this question on some forums.
It's not that difficult a problem to fix! You cant afford an alarm clock, no problem - get your parents, or a sibling to wake you up. Surely you live with someone else in the house, surely they dont all get up after you. Get your shit ready the night before, pack your bags, make a lunch of watever the night before. I used to do it at school, and it just makes life easier. Thatll cut some time. Then push yourself in the mornings, dont dawdle about. I HATE YOU. If you are running late, walk faster or even jog a bit to school. Sure if will suck, with a port on, but if you dont want to get expelled; do it.