Avalon is selling for so much more because they CAN. They have a product in hand that nobody else can really compete with at this point. Why would they sell it any cheaper? If/When BFL gets their asses in gear and starts shipping a product, Avalon will have to bring their prices down to whatever the market forces are driving.
And if they really wanted to maximize their profits, they would artificially delay shipment of round two and three, while collecting more
BTC780 10k chip bundle orders.
That way, they keep people from getting scared away from ordering the chip bundles by a skyrocketing network difficulty.
Not that I necessarily believe that's what they are doing. But that would certainly increase their profits...