Well I can't imagine paying that much for it, but to compare it to other multi million dollar cars it was. It was the only survivor of two cars and is the top dog model of the most prestigious American built car ever made.
I watch the auctions every year. An older friend of mine goes every year to keep up on the going prices. He owns many high end cars including an all original Boss 429, '68 GT500KR, two other Shelbys, and about 7 other Mach 1'*. I love classic Fords and am even restoring one('66 Mustang coupe). That being said, I do not think this car is worth 5 million dollars. I think that is a ridiculous amount for any car. I don't know what they smoke out their in Scottsdale but whatever it is I want some.