This is a tricky question. Amtrak only goes to north station. Then I think you take the red line and the orange line to south station. Therefore, its 42 to 62 as per above for Amtrak ( check to see if there are specials, which need to be booked in advance). Then you would need a Charlie card or per round trip ticket for the subway. I think that's about 7 dollars total. Edit: if I were going to south station from Dover I'd take the c and j bus. I believe that is about 40 bucks round trip and it goes right to south station.
They range from $42 - $62 per person on Sunday.
I don't know the price of the trip
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