How do I acquire this property from my Neighbor?

[Robert Crocker]

Hey guys,

My purpose is not to be morbid, but this is the situation at hand.  My neighbor has verbally committed to selling me his property upon his death.  He is 90 years old, and none of his family members will be able to afford the property hence his commitment to giving me first look at the purchase when this time comes. 

Being that the market we live in is always RED hot and definitely expensive, it's the exact market where bidding wars create massive purchase prices.  My hope to avoid any competition by constructing a legitimate deal with him prior to his passing.  

Does any one have any ideas on how to contractually acquire this property while allowing him to live in property until he passes away? 

Should I buy it now and let him live rent free? 

Should get some sort of documents created to secure the asset to me upon his death while maybe incentivizing him with a small cash payment (Or paying some of his utilities) every month that would ultimately be deducted from the purchase price?

How do I contract this deal so it's a win for him and win me?

Thank you guys!

-Robert