I would recommend would be to try to contact the distressed seller right after the notice of default is issued and try to negotiate a deal directly with them.
Will the seller at that point have rights to negotiate? I guess, the lower limit of the price they would accept is the amount they owe (which must be a very high percentage), and even in that case the seller will not be motivated to sell for that much, since they will lose their entire downpayment. Right?