Need About $700 by March

My friend and I are shooting to go to PAX East this coming March and I somehow need to round up about $650-$700 by then to cover tickets and hotels (parents might be willing to cover food and gas expenses). I've thought out plans, I found a hotel under fifteen minutes from the center that isn't too expensive (researched three-night deals), and I should be set to go if my parents will let me miss a school Friday, and if I get the money. How can I get the money by then? I don't really have time to get a job (starting school again the 29th), am I able to get an after-school one? Who would hire a fourteen year-old part time? (It's legal in my state) I also have to account for afternoons after school in which I have the musical.

I'm very open to suggestion at this point.