There weren't too many choices of roadster sports cars in that era. The Jags were closer to five grand. The MGs and Triumphs were usually under three thousand. The $3500 price sounds like it could have been an Austin Healy 100 or 3000. The AH Sprite was under three thousand. Of course, the writers might not have had any particular car in mind....they might have just thrown that price out there.