Aston Martin was created by Lionel Martin in 1922. His car company won at a competition called Aston hill climb. So he called his company Aston Martin.
No, it isn't. V12 Vanquish S is the fastest Aston Martin (now).
Yes. :D
An MG Mgf produces about 130-140bhp, depending on the model and spec.
New cars range from £80,000 to £170,000. A used Aston Martin locator can be found here https://used.astonmartin.com for used prices.