Buying grandma's rental in Palm Springs

[Casey Olson]

Hi guys, 

First time on here. Love the content. Very helpful. Background: I live in Washington and am going to buy my grandma's retirement home in Palm Springs, Calif. and use as a rental. She is selling to me for a sweet, sweet price. She is on a tight income, my grandpa died a year ago and she is now living in an assisted living facility in Seattle. 

I could just pay her cash for the property, but want to make sure she gets the best deal, in terms of taxes, and don't want her to have to do a lot of work on her end. I just want to make it as easier as possible on her. What would be the easiest way to cost her the least amount of money and time? Could she gift it to me? Should I just give her the entire amount in cash? Should I just pay her a certain amount every month and she could sign the property over to me?

Hope this makes sense? I just want to do what's best for her. She also recently sold her primary home, which she will have to pay taxes on. 

Thanks for any advice