Swiffer Sweeper 2 in 1 Mop and Broom Floor Cleaner Starter Kit for only $6.99 if you have free Prime or Amazon student shipping! Right now its market down to $8.99 so all you have to do is "clip" the $2 coupon on the same page (make sure you are logged in to see it).
Holly and I are both big Swiffer fans, because they are really easy to use, take up almost no space in a dorm room and you can purchase generic refill pads or easily make your own. The last two years we've had roommates with the swiffer base, so the two of us actually need one (aka Holly: grab this for us and I'll pay you half back and then I won't have to cart it out to CA next year?). I've never seen it for less than $12!