get a programming kit. Then maybe some omni wheels, a tread kit, and gear kit. Some more motors/servos would probably be a good choice, and if you feel like it get some more sensors, the only sensors I have used frequently are the limit switch and the encoders.
I got most of my parts from radio shack on sale, and maybe one near you still has some parts.
I also have most of the KOP sensors, including a CUMCam, on my current vex bot, but your team might not let you take as much home.
