Handing fare inquiries from users unfamiliar with Amtrak's fare structure would require quite a lot of good programming. Amtrak sometimes offers promotional fares in certain markets. Special fares apply to special groups like senior citizens and persons attending a particular convention. Fares depend on type of accomodations chosen. The zoned fare plans like the Air-Rail Plan and All Aboard America have special rules.
Fares can depend on the day and time of travel.