My wife and I are thinking about doing our run from Barcelona to Sevilla via night train. This will strike a nice balance between the cost of a hotel and a day train while not taking up time during the day that would be better spent walking around. I mocked up a Renfe booking for the same day this month (March 2009 trip) to get an idea of what the time schedule and cost looks like. The problem is I don't understand their bed prices. Ideally we'd have a 2-person car to ourselves. But the bed prices don't seem to describe what you're getting for the different prices. I posted a screen capture of what I'm talking about at: http://tinyurl.com/6mvo7w It's a photobucket site that was too long for direct link.
I don't exactly have an answer for you on the train. But also for time and cost savings- consider a flight. I flew Vueling airlines from BCN for 28 Euros (last September), and it was a 3 hour flight.
I actually had the same question when I was planning our exact same route a few weeks ago.
My wife and i will be traveling at the end of august and we chose to fly that route. The tickets (with all baggage fees, taxes, etc included) worked out to be 50 euro/ticket. It's an hour and a half flight that leaves at 10:00am and gets in at 11:30am. We thought that would be a much better (and more comfortable) option than a night train. I think in our case it worked out to be cheaper too.
Just something to consider... we're flying clickair.
That may end up being the way to go. I'm guessing for two of us in a 2-person sleeper would likely be in the 150Euro price range. So that is a high cost.
It looks like Clickair has the 10kg carry-on limit (~22lbs). One thing I did notice is that Easyjet has no weight limit for carry-on as long as it fits the size restrictions (and is can be reasonable stowed overhead). I didn't check to see if they do BCN-SVQ.
How far out is the airport from town? What kind of costs will be expected for that transfer too?
It could end up that we do nothing but short-hop flights on this trip for most of our destinations.
The costs list the accommodations as you go up in quality and price....unfortunately, you can only book the seat over the web...not the sleeping accommodations (why?....who knows!). Usually, RailEurope is much more expensive...but in Spain's case, they're usually not. You might try them....they have four-person sleepers from $137 (they're gender-segregated, unless you have four people travelling together) and first class single compartments from $246, which compares favourably with the 150 Euro price you've seen listed. RailEurope has no double compartments listed on this train....I thought there were some....so you may want to call them to inquire.
If you take the airport bus, it's about 40 minutes from the Placa Catalunya area to BCN. See http://www.emt-amb.com/links/bus.htm and choose "Aerobus" from the dropdown menu (near the bottom.) Cost is about 4 Euro pp. Taxis take 20 minutes and cost about 25 Euro. In Sevilla, the airport is just to the northeast. A bus runs Santa Justa railway station, the down the eastern fringe of the downtown to the Prado de San Sebastien bus station (on maps.google.ca at 37.381407, -5.986363). You can either transfer to another bus at Santa Justa, (bus 32, to Plaza Encarnacion at the top end of Sevilla's tourist district, 37.392766, -5.991846), or cab it from the bus station to downtown. Clickair is a great alternative though....new airline with nice new A-320 airbuses, a subsidiary of Iberia....it just signed a merger deal with vueling. You can compare fares with vueling, and Spanair...even Iberia itself.
The bus into the center of Barcelona- I think it was red, is the way to go unless you are not staying within walking distance to your hotel. It's cheap, clean and they run frequently.
In Seville I opted for a cab, which deposited us at the hotel doorstep. Seville streets can be confusing to a first time visitor.