I agree with Miyori. If you are unable to find anyone, and are able to take the train (with your costume load, etc.), I suggest either Amtrak or Metrolink. You'll have to stop over in LA on Metrolink (and switch trains), but you can get a nonstop ticket with Amtrak. Granted, Amtrak is a bit more expensive. There are two train 'stations' in Van Nuys: the actual station, and the Flyaway station (you take a bus from the station to this stop, which is right outside the Van Nuys Airport, which is right next to the Airtel hotel, where ALA is held). From there, a taxi should not be that expensive, and I also hear that the hotel can pick you up as well if you are staying there.
Hope this helps with alternate plans ^_^ Good luck!