anyone know how much a heritage ford gt with 5.8 miles is worth


You may be better off finding one for sale with about 3,000 miles. That way you avoid the hefty premium of a no-mile car, and avoid the potential mechanical issues of a garage queen that has been sitting, all for a lower price. 3,000 miles or so is better than 36,000.
 
There's a 9600 mile Heritage in Ebay for $200K.