In March my wife and I are going to be in Madrid and need to go over to Barcelona. We could fly but the train seems better. Purchasing plane tickets is easy but no so with train tickets. If we go by train should we buy tickets ahead of time (in the states via internet) or buy them there?
Buy them up to twelve weeks ahead and you can find some great deals. In August, my train ticket from Barcelona to Madrid was 38 euro. Even the "turista" class is like a first class airline seat - lots of foot room, foot rests, large tray tables. I loved it. Register on the Renfe site before you try to buy your tickets. If your credit card is not registered for Verified by Visa, they will have you do that during the purchase process. You can switch the website to English in the upper right corner.
Follow Nancy's advice....read this article on Trip Advisor for more information:
Madrid Traveler Article:
Madrid: Buying Renfe Tickets Online
Have been trying to buy tickets for May 2, 2014 for Santiago de Compostela to Madrid on the Renfe website. First of all the Renfe site is a rabbit hole warren of confusion. Some said it was like Alice falling through the mirror. Don't feel as if it is just you. Oh, and don't look for a British flag or even US flag for language conversion. Look for the words in different languages that all mean hello, or welcome. English is WELCOME. Even after that don't expect everything translated. So have a Google translate page open so you can attempt to understand what the pop ups, that seem to be blocking your progress, mean.
Notify your credit card that a purchase from Spain is coming through before you go to the Renfe site. Or you will most certainly be turned down, and the Renfe site will not say why.
Glad to hear mention of the 12 weeks in advance limit, as May 2 requests come back 'information not found' or something like that. Nothing helpful like, tickets can only be purchased 12 weeks in advance.
I did get tickets one-way Madrid to Barcelona for $66.50 for March 31. Quite a discount from the advertised 100 Euro plus found other places.
wayne iNWI, where it is -12 and falling
You have probably bought your tickets by now, but in case you haven't, I can add this recommendation. Last year I had to make the same trip from Barcelona to Madrid, and like others was bewildered by the Renfe website. Following a suggestion in the Trip Advisor article referenced in an earlier reply, I used the Petrabax.com site. This is a US site that is easy to navigate and takes US credit cards with no problems. They do add a fee to the price posted on the Renfe site, but I thought it was reasonable.
We flew because of time.