Yes, any time you take your foot off the gas, the car’s momemtum will start charging the battery. In addition, the battery will be gradually charged up as you drive. One of the main advantages of a hybrid is that you cruise in a high gear, and to pass quickly, the battery kicks in and you get a big boost. On a high end hybrid, the electric motor is called a “green supercharger”.
From a purely economic point of view, a Yaris or Honda Fit will cost less per mile to operate. Where I live Prius cars are bought by people who are making an environmental statement (my dentist, for instance), and who don’t really need one for economic reasons. Our family doctor has a Toyota Highlander Hybrid.