What kind of camera are you using? For that kind of money, you're probably limited to a boom mic connected directly to your camera, recording audio straight to tape. That's assuming your camera has a mic input.
Best bet might be to try to find a sound guy with his own gear who's willing to work on your project for screen credit, a copy of the finished video, and a meal. They're out there -- believe me.
If you need a boom mic, best bet is probably the Oktava MK012 from Sound Room -- under $200, which leaves you plenty for a good boom pole, wind protection, cable, etc. Connect straight to the DVX100b and record audio direct to tape.
If a lav is more what you're looking for, I don't know how to advise you -- but somebody here surely does.