Every thing is negotiable and it must be a wining winning situation. Get comps form your agent to establish the actual market value.
RE/MAX Metro Anaheim
Talk to a real estate attorney.
Is it a lender approved short-sale?
If not, you will incur the deficiency of the mortgage as well.
If it is an REO (Foreclosed, Bank owned home) you don't have to pay the property taxes.
The property taxes are cleared before the house can be sold as an REO.