Found at the thrift store for $5.95. Dated 2000 so it's about 11 years old. I haven't seen one offered on Ebay, so I think it might be a rare one. The box is a bit rough, but it's still factory sealed.
Not a rare set, but like most Mattel sets, they disappeared from circulation very quickly. That probably isn't the definition of "rare", but certainly like a lot of other set cars, difficult to locate.
There are actually two versions of those cars, one with Viper on the side (just behind the front wheel well), the other without. Both came in the same numbered set. If the set you've got happens to be "Viper"-less and you'd like to trade, send me a PM.