It's possible you're already getting a great deal, and the builder feels you're being greedy. We have no way of knowing, since we don't know your market, nor the details of your deal.
Maybe you're talking about a 50x100 lot.... or 16 acres... (obviously the cost of Fencing would vary dramatically)..
You have to make the decision as to how important the Fridge and Fence are to you. If the builder won't supply them, do you no longer want the property?