Actually, after seeing a roadster in Mazatlan last weekend, I had the same thought myself. Of course, the only smart roadsters you can get
anywhere are used, and anything you buy in Mexico is going to have several years of south-of-the-border wear and tear on it. And insurance would be a bit of a problem.
Still, you can get something like this
gray 2004 roadster with 50,000 miles on it for 160,000 pesos -- less than $11,000.