After seeing how long it can take by train and the fact that we are limited with time, I think I will take the suggestion of flyng from Barcelona to Paris...2 hours and a lot cheaper too.
But remember, that's 2 hours in the air. Add 3+ hours at the beginning to get from your hotel (probably just blocks from the train station) way out to the airport, go thru security, be there the pre-requisite 2 hours before the flight time, etc. Then another 3 hours in flight delays, de-planeing, luggage, transport to your hotel in Paris(again, probably near the train station).
Add that you could do an overnight train (and maybe even upgrade to a private 2 person cabin - you said it was "we" who are travelling) to save a night of Hotel room in Paris, and the economics might make sense, too.
I'd investigate Tim's suggestions in your original post. But that's just me, and I like trains!
Norm, thanks for doing a lot more of the research. Given what you propose, and the fact that I seem to be able to sleep ok on night trains, I'd probably still vote for the night train for myself. Ultimately it's up to each individual person to figure it out for themselves. Good thing is that we all have done enough of the research to give Kathy enough info to really make her informed decision.
I'm always up for having someone change my mind. You certainly gave me more to think about.
To add to Jason, also remember the cost to get to/from the airports in Paris and Barcelona. That's a hidden cost that most people forget about.
You can save the cost of a hotel room by taking a night train from Barcelona to Paris. You maximize your time by traveling while you sleep, and maximize your money by not paying for a hotel room in Barcelona or Paris. Yes, the sleeping car is a little more expensive, but not as expensive as a hotel room.
Per Jason, that 2-hour flight could take you 5-10 hours going door to door from hotel to hotel even if everything goes smoothly. A night train is about 12 hours. Also, planes are much more dependent on good weather than trains, which maximizes your risk.
Just make sure you crunch every penny and every minute that you're going to encounter!
I feel compelled to stick up for the discount airline flight, especially with some of the other information regarding train travel being presented. I, too, love trains...been taking them for 45 years, ever since I was a kid. But one big question is whether you'll be able to sleep well on a train, and arrive in Paris refreshed and ready to go. I've always found overnight European trains stop far more frequently that North American ones...the Cerber-Paris run makes 13 stops in its 10-hour run...luckily, (I guess), only 5 after 11 pm....and no refreshing shower in the morning. And gentlemen, please....let's not overstate airport times! Barcelona airport is a 40-minute bus ride from Placa Catalunya, and you only need to arrive 90 minutes before flight time, since it's a domestic flight. As for the other end, luggage and out of the airport in an hour, if that long, and a 45 minute RER ride to Gare du Nord. (more)
(con't) That's still only 6 hours versus 12, puts you in a nice comfy hotel, and gives you an extra evening to enjoy romantic Paris! If you're concerned about the cost of the "extra night" at the hotel, stay at the comfortable Etap hotel near CDG for about 40 Euro. You'll also find that, from about May through October, the fares on this route sell out VERY quickly...if you don't move on the day, and sometimes the hour, they're available, you'll lose out, and end up spending a lot more for rail travel. Yes, there are benefits to taking the train. But let's not throw up all sorts of scary "facts" to justify one over the other. BTW..cost of getting from Barcelona to the airport, and CDG-Paris, under 13 Euro each.
Norm and Jarrod have both added a lot to the conversation. I think it boils down to what both alluded to: How do you feel about trains?
I myself would err on the side of the train, even if it cost a bit more $/time (and only when I can afford a private cabin on an overnight). I find them so romantic and I sleep like a baby on trains! Well, me and the bottle of Rioja, Beaujolais, Chianti, etc that I pick up at the station! :)