no, if MtGox exchange is short BTCs, the low price of BTC on mtgox is FAKE. there are no BTCs to be bought at $250. The price of $250 is probably
( (Actual number of BTCs on mtgox) * Bitstamp price ) / (Number of BTCs that mtgox is representing they have)
You are assuming that someone stole more BTC than MtGox total profits divided by $250 (see how a low number here helps MtGox?).
And even if this is still the case, like I said, they could borrow against the fiat they are holding for their customers.
no - you cannot use $250, must use Bitstamp quotes. see how the low prices hurt them? Again, this is all assuming MtGox is shutdown and goes into liquidation. If these low prices do in fact attract more deposits, then yes, low prices help and it is in fact a ponzi scheme.. like MfGlobal.