One thing I didn't see mentioned is that when the parents pass away you will be dealing with their children. In all probability they are going to want to sell the house because they will want the cash. I think the only way this makes sense is to let them sell you the house and then they carry the mortgage. If they pass away and you are not in default on the mortgage then they have no right to foreclose. Personally I cannot imagine a young couple taking on a home this size. I still don't understand how many of the people afford to live in California. You will need to consider repairs over the years and taxes and insurance. What is your status now? Are you renting or are you purchasing you home with a mortgage? On the surface this looks like a big nut to crack.