Here is a 66 K code Koupe listed on Ebay by seller "matt1964mustang" with a starting bid of $4,500.00:
1966 Mustang K Code Coupe. It has rust but is very build able car. It has spent its life in Oklahoma. The car is a 1966 mustang K code 289 HIPO rare Ivy green metallic with black vinyl roof. The roof is in great shape. The rearend of the car is it’s original 9” which is worth 2500 in its self. The motor and transmission are not original to the car or HIPo. The motor parts and transmission for Hipo cars can still be found at swap meets. I have assembled three of them through eBay and swap meets. Happy hunting. This is a chance to own a rare piece of Mustang history. There were a lot of 66 mustangs but not 66 k code mustangs. The luck winner is required to make a 1000 deposit with in 48 hours and make contact with me to discuss final payment/shipping.
Good luck bidding, Matt