Just call 3 contractors in New Jersey stating you just moved there and need rough estimates. Hard to say how many hours were involved, any surprises, cost of materials.
Sounds high but lots of variables can alter/raise the cost of work. Buyer's remorse after the sale though has fingers pointing both directions on this situation.
Make sure you explain to your 88 father that you must be included in all financial transactions over $500.00 from here on out. Problem solved.