I would wait out ebay, I'm sure you could find a 600 headset for $20-30, less if you're patient. Look for dirty headsets, with bad pictures, they always sell for less.

A while back I won this Dura Ace 7400 headset for $15, plus $5 for shipping, I was the only bidder: http://cgi.ebay.com/ws/eBayISAPI.dll...:X:RTQ:US:1123

It cleaned up really nice too.