Help on financing an opportunity

[Nicholas Ferraro]

I have an opportunity on an off market SFH.

Owner is asking $250k. Home has a pool, hot tub 1600sqft, invisible fence for dogs, everything has been updated including appliances. Fenced in backyard. 

Owners equity approx $20k. 
owner wants to build a new home but needs funding from the sale. 

Let’s say I have 20k I’m able to invest into this property out of my own money. What are some ideas to get him covered. And be able to build a new home. 

He says he needs $105k because that’s the difference of what he owes, 145k and what he wants to sell for, $250k

I’m thinking sub to but not entirely certain how to go about it. Or maybe it’s not a good opportunity. 

reason for selling, wants to move to country side. This is a property in the suburbs of Greece NY

Any tips/ advice is extremely appreciated