Thanks again... and oh, are you lucky, being so close to Mexico. I'm on the East Coast.
Yes, it's only a two hour flight to Mexico City, whereas it's over three hours to New York.
Flight time's one thing; cost is the other. (I bet that's true for you as well.) it's funny how Amtrak and the airlines seem to jack up prices in an arbitrary way. When I lived in D.C., a round-trip train ticket to NYC cost several hundred dollars. Now I live up in PA< and a round-trip ticket to NYC costs less than 100.00 bucks. (Though I'd have to change in Philly to get the Metroliner or Acela.)
Basically, Amtrak ticket costs are far higher if you're *only* traveling on the NE corridor lines. Book a ticket from a bit further west, and it's so much cheaper, even though you're actually on a NE corridor train. Go figure!
American Airlines has quite a few flights out of DFW to both places, so with a little planning relatively inexpensive fares are often available to both New York and Mexico City. It can be very arbitrary though--earlier this year I made two short notice business trips to New York, and the fare each time was $2000 for coach. Yet at about the same time I also booked a seminar trip in advance, and the fare was only $200.