unless its a GT350, which is made by carol shelby, who made the cobras, then not that i know of. there was a mustang cobra in the seventies, or that was its nickname, it was really a Ford Mustang II. but i wouldnt go for it, do u have pics? its most likely some redneck trying to get the most out of someone who doesnt know mustangs.
The Mustangs Carroll Shelby (of Shelby Cobra fame) were called the Shelby GT 350. Typical equipment was a 271-horse 289 V-8. A version with automatic transmission was made for Hertz. It came in black with gold stripes and was called the GT350H. All were fastbacks.
If the vehicle's seller doesn't have the nomenclature straight, I would be suspicious. A decent GT350 would command a premium over and above the price for a decent lesser 'Stang.
Shelby took a Mustang and modified it into the Shelby 350 and later the 500. "Cobra" was never officially added as part of the Model name.
Shelby also took an English AC sports car and made the Cobra. The Cobra was made between 1963 and 1967.
It wasn't until 1976 did Ford combine the two words with the Mustang Cobra II and again in 1993 on...
Although the Snake was prominant on the Mustang, it was not officially added to the car so not to confuse the Mustang with the Cobra -- both in production at the same time.
The fact the guy said it was a Cobra tells you how little he knows his own car. A real Shelby with have a Shelby ID plate in the engine bay. Write down the number and check with the Shelby Resgistry for accuracy.
It's most likely a popular clone. Unless it is verified by a qualified Shelby appraiser, stay away -- unless you are paying standard Mustang prices.