My school has been doing a lot with recording classroom video using small digital video cameras (mainly kodak Zi-8's). The cameras take decent enough video, but the audio is pretty poor in a larger classroom. However, the Zi-8 has a minijack mic input, and I was thinking of purchasing a microphone to better record the classroom audio. Ideally, I'd like a 2 mic setup, one wireless lavilier mic for recording audio from the teacher, and then a wider area mic for classroom audio. Is there a reasonably cheap setup that could do this for less than $500?