The Hardened edition usually is reserved only as it was only for sale for pre-sales. So I would sell ONLY to those that had it preordered until after whatever time limit the preordered copies are held.
We only got a few Hardened editions for xbox. I don't think we got any for the PS3. We got way more pre-orders than hardened editions. Pretty such there was a message board or something about the preorders for any game ony being for standard editions.