Until the preorder date closes, or when retail stock is exhausted. After that you're off into the wild-wild west of the secondary market.
In all seriousness, the really good items seldom show up on the secondary market. If there is something you really-really enthusiastically want, preorder ASAP. Wait too long, you may find a dealer that ordered extra. Miss steps 1 & 2, good luck. You may or may not ever find one.