It's more like one million of empty promises per sucker, most of the "funds" there probably were imaginary.
Well, if each contract was 400'000 HKD minimum ( = 52'000 USD = 230 BTC), and there were 3000 clients, then the scammers stole at least 150 million USD of real money from their victims. At current prices that would be 680 kBTC.
It may be bigger than MtGOX, because we do not know how much MtGOX clients actually lost. The 660 k BTC / 500 M USD figure is what they thought they had in their accounts, which (as in Madoff's case) may be a lot more than what they actually put in.