I'm in contact with the son of an absentee owner of a house next door to the one I'm currently flipping. House was used as a vacation home.  The son is wanting his dad to sell because his health is on the decline and cannot travel. I contacted the son and he is motivated to sell and said he can convince his dad but only if the price is right. We have come to a stand still and are about 30k apart on price. Any suggestions how to get things moving and come to an agreeable price?

You don't, if the price isn't right for the seller move on to the next property and if they change their mind they know where to contact you.  There is nothing you can say to someone to get them to sell their house.