Or take the 12 bus from the White Plains bus station (across from the Metro North train station). Schedule: (warning: PDF) 
Purchase does not have a wide variety of food options. However, there are a few, and by a few 2 to 4 restaurants down Anderson Hill road past Purchase Street. In addition, there are two colleges in purchase (Suny Purchase and Manhattanille) which possess college food for students to eat
Purchase is located within minutes of Westchester County Airport (HPN) offering a variety of non stop flights to many places in the country. In addition, Purchase is close to Metro North, an easy way to get in the city. To get to the city, one could either take the Harlem Line from White Plains or the New Haven line from Harrison.