Hey Sniper,
Is it NIB, used, the older style or the new enhanced model? If it's NIB, and an enhanced model, I wouldn't give over $350. There's one in a local gunshop here, enhanced and NIB and they're asking $350. If it's used, maybe $250-300. I picked up my CD FS used for $200. It was almost new in the box w/ 6 extra mags.
Hope this helps. hunter