said by Light Guy:
The least expensive Acela seat between NYC and Washington is $155 compared to $49 for the Northeast Regional service.
The Acela Express is an hour shorter and Business Class seating which would cost an extra $37 on the least expensive train.
The least expensive rate between NYP (New York Penn station, the correct shorthand to use for Amtrak) and WAS (Washington DC) for Acela is usually $133, not $155. I took an Acela WAS-NYP last Thursday for the $133 rate. The Acela is about 35 to 45 minutes faster than the Regionals between WAS and NYP, not an hour, because of the limits of the NEC which needs a lot of bridge, track, and catenary replacement work.
The Acela may be more expensive and only modestly faster than the Regionals on the Northeast Corridor, but they are frequently sold out, so people are willing to pay for the Acelas.
Wish Amtrak had turned on the free WiFi last week but so it goes. It was announced months ago that Amtrak plans to add WiFi to the Regional trains on the NEC sometime in later 2010.