Alereflammams would know better but I believe the cheapest might have been $575 if I'm remembering correctly. I'm not sure what he can get but it wont be anything close to what he is asking. Maybe someone would bite at $600 but I don't think he'd get more than that.
The JVR signed Bower jersey showed up on Kijiji about 3 months ago with an asking price of $450. I tried to offer $350 and the seller did come down to $400 but I passed and it was pulled about a week after that. I'm sure the person sold it but not sure for how much.