Creative financing on a Triplex

[Marc Shin]

I found a triplex for sale that has been fully renovated for $480K.  I want to see if I can acquire this property via seller financing.  I’m completely new to investing and to creative financing.  If the seller is open to seller financing, I was thinking of putting in a full price offer with 10% down and maybe terms of 30 years with 4% interest rate.  Does this sound like a reasonable offer to a seller?   if not, what would be reasonable terms that a seller might agree to?