It looks like we're back to a familiar conundrum: should I buy a supercharged Mustang or a base Corvette? A base Corvette coupe starts at $49,515 with destination, and the only option that you'll really need is the two-mode exhaust system at $1195, so a worthy Vette starts at $50,710. That's actually $185 less than this particular Shelby GT500 coupe (and that's ignoring any potential dealer markup on the Shelby). Yes, the Shelby has more horsepower, but the Corvette is a better handler, more fuel efficient at 16/26 mpg, and 707 pounds lighter. By no means is this an apples-to-apples comparison, but it's certainly one that will be explored on many Web sites.
Ignoring the Corvette question, the Shelby GT500 is a riot. Mustangs and superchargers go together like beer and pretzels -- even if you don't particularly like the combination, you can respect its popularity. With horsepower and torque ratings well above the magic 500 mark, there's a lot of power to play with. These Goodyear Eagle F1 tires require a good amount of heat before they start to grip, so giving the Shelby any noticeable amount of throttle around the first few turns results in an immediate (and enjoyable) loss of traction. I didn't have a chance to explore the limits of adhesion once the tires were at operating temperature.
The key to understanding the Shelby's $18,330 price premium over a Mustang GT is the factory warranty and availability of parts at regular Ford dealers. Yes, you're getting a supercharger, a six-speed manual transmission, and some other go-fast goodies, for more money than the aftermarket may charge, but Ford is willing to stand behind this vehicle and guarantee that the key components will stand up to daily use. You simply can't get that peace of mind from a collection of bolt-on parts, and this price premium is consolidated with your regular monthly payment, not sitting on high-interest credit cards.