Short sales are done with the lender's cooperation once an offer is accepted by the seller. Let's say you offer $30,000 for the lot. She has to then work with the lender to accept this as a short payoff for what is owed ($399k). The bank may or may not do that depending on what the lot is currently worth, what their cost will be to foreclose, and how long it may take them to complete the foreclosure. There's a lot of information you haven't provided so it's hard to give you a better answer.