How do I buy this house while helping the owner?

[Todd Ashley]

It's been a while BP and I could use your guidance! Here is the situation:

I know an older women who had a stroke and is currently living in her daughters 5th wheel so that she has assistance. The women desperately wants to move back into her house and her kids want that as well, but are afraid that she is not ready to live alone again. They have considered transferring the home over too a care facility in trade but then they are losing their entire inheritance. I would like to offer to purchase the home from them by giving them a down payment that will help pay for in home care and allow the home owner to live the remainder of her life in the home. After she passes away I would owe the remainder of the previously agreed on price (or it would turn into an owner financing agreement). The home is located in Portland, Oregon which is one of the hottest markets in the U.S. with virtually no signs of letting up. Is this a crazy idea? How could a deal be structured to ease their capital gains tax? The house is owned out right (purchased for ~35k) and is probably worth ~300k-325k in its current shape. Any guidance is greatly appreciated!