As a parent, you can also gift down payment to your child to help, so that should cover all the basis.  

And what a gift from your grandma, plus your mom being open to you leveraging this property.

Why do you think he is basically giving you a $30,000 gift?

@Marco HerreraWhy not get Grandma to do a gift of equity and then refinance it for cash out within the next year?

when you sit around and don't take RISKS, you RISK destroying what is the ultimate gift - your spirit.there's nothing like seeing a person without hope - it hurts, even when it's a total stranger.

If she's giving it to you during life then it's likely a gift. 

because 1. you cannot get an FHA loan (or any conventional loan under 80% LTV) if you are not living in the unit for at least 1 year. 2. you can only get "gift funds" from your friend as a downpayment if its a primary.

@Fausto Carosella   you have a good piece of wood I can whittle you a gavel as a gift to the court, may be they'll go lighter on you  for filing wrongful liens and financing the sale of real estate outside of settlement, you know, like undisclosed costs of acquisition in connection with the sale that cause the settlement of accounting to be incorrect, an unreported basis for federal taxes and, oh, let me see, financing an option out of compliance with the SAFE Act (now incorporated in Dodd Frank)........hey, mind moving that spittoon away from your leg, I'm not a very good shot spit'n'!   

Might speak to your attorney or accountant, if his estate has not been settled, you can forgive the note, as a gift and avoid tax issues, if the amount quaifies under gifting matters.

You can receive a "gift" from a family member but not a friend.