What is the fine-grained topic of the following text: In the U.S., it will come in two guises: The base model, at $72,000, with a 345-horsepower version of the Maserati 3-liter, twin-turbo V-6, and the S, priced around $83,000, with a 424-horsepower version of that same engine. Only return the topic.
U.S. prices and specifications for Maserati models