I had quite a time trying to price the car, and I would admit I definitely got it out the gate for sale way too late in the year. People that I have talked with haven't brought up the price in conversation but are more interested in details and issues of the car.
I didn't use a price guide since they seem to be omitting a ton of information about these cars and the one guide I have from 2016 seemed to "penalize" the GT if it had a 440 in it, so no percentage multiplier according to their rules (by using their logic you could actually have a more valuable 1970 SF formal top car with a 440 with everything else being equal no AC, etc).
I used current GT cars for sale and those that have sold and were for sale at one point as a base point, this is what people are paying. This car is rough from the outside and it needs total and completion of the body as well as items chased down: exhaust tips, washer bottle, more things in list, etc. The interior on the other hand is okay other than spot in headliner and tear in pad. The engine is rebuilt though not stock, the bottom of the car is very soild, so it is not all rough and is partially completed. The "plum crazy" color firewall is a drawback but at least it isn't rusty.