Chances of a store actually HAVING spare systems for a few weeks after the intial release is pretty much 0. Look at the 360, it took a while for 360s to even come into circulation after the intial launch.
I knew people selling PRE ORDERS that were 50 dollar pre- orders for 100-200 bucks so people could actually GET a preorder. Somehow these kids were allowed to preorder more then 1 or they used multiple stores. Quite a ingenious plan. I think i might do that. Plunk 50 down on a PS3 then sell my 50 dollar preorder for 100 bucks.