I would have put $50 down now, secure one knowing I can keep saving till release date, walk in and back out with a shiny new Xbox VS having to explain to my wife why $749 has suddenly disappeared from our account to Xbox.com.au or Harvey Norman.
I think the first scenario is the safest.
It's a shame it's turned out like this for both consoles. Used to be able to walk into a retailer and buy it, not hypetrainpreorderhopeyougetonestiffshitifyoumissed out crap.