No they didn't. Saleen took a fully functioning Model S and tokk out Tesla's branding and put Saleen branding on it. This is not the same thing as buying a chassis from Lotus and building everything else (drivetrain, battery, electronics, safety features, etc.).
Here, you said it yourself. The Elise was just a glider. Of course the Roadster was going to be more expensive than a glider! I mean come on.
Ac made the powertrain for the Mini years ago and it was a flop. Apparently they have no involvement with the i3 and i8.
I don't care what they are doing with the mustang. You were comparing the Roadster to the 416.