Typically, Amtrak ticket prices vary throughout the week. For those who want to book trains for less, booking on weekdays often results in cheaper Amtrak tickets compared to weekends. If youā€™re trying to save on Amtrak tickets, Tuesday and Wednesday may be the cheapest days
Source: https://www.devex.com/people/what-s-the-cheapest-day-to-buy-a-train-ticket-2079141