There's simply too many people who will buy at ~250-280, don't expect a lower drop than that. If somehow we go below, don't expect it to last long and grab your cheap coins.
I think one factor that effects that is how fast the drop happens. I remmeber, when the price was around 450, then people used to say if it would go to 300, then they would buy 50K worth of bitcoins. But the drop was happening really fast, and a lot of them didn't. However the high 200 , and the low 300 does look like a stable bottom for now.