At $280/per day for a hotel could just as well be $150/day for hotel which leaves $30/day for a rental car, will leave you $100/day to use for other incidentals such as meals and other things. My point is, maybe spend less per day for the hotel and get a rental car. Maybe consider staying at a timeshare resort and just commute in the car or minivan all day. If you dont have a car and rely on hotel shuttles, it will not be as convenient as having a vehicle. Its not that less expensive either. BUT.....I see you are staying at All Star Movies, so you are on-site and do not need a rental car. It sounds like you dont mind using disney transportation at all. So problem solved. A budget of $280/day for a hotel room is expensive unless you are staying onsite. Staying onsite for $280 already includes the convenience of Disney transportation. Have a Fantastic Time!!!
But note that many offsite places charge for parking plus you have to pay to park at Disney...so you could pay $30/day for the rental and then $40/day on top of that for parking