I paid $550 for a Cannondale Hollowgram SRM spider with chainrings two summers ago.
Just keep looking on eBay, Paceline, Slowtwitch and Craigslist.
For CL, the trick is to look in other cities. I found my SRM on Craigslist in LA. Exchanged several emails with the guy and chatted with him for about 5 min. on the phone before making the deal. Used PayPal for the purchase to give me protection.