seriously there's no way in hell the actual transaction is worth three hundred million Earth dollars
it'll be some sort of mob deal, and it'll make sense at that level, and we'll never know
It could simply change hands for an undisclosed amount equally to or greater than tree-fitty.
Or something far less on the pre-condition that MtGox is placed into Chapter 11/ bankruptcy/whatever Japan's restructuring framework allows first.
Seems doubtful that a buyer would offer a full bailout, any corporation as insolvent as MtGox would likely have some kind of partial settlement to creditors (customers in this case) as a takeover precondition.