Not sure anyone answered you, but I only ever used the official barca site, I don't trust others when I am spending 500 odd euro for flights, accom and tickets. Only ever got the tickets I wanted too. front row . Pick a seat you want and keep checking back as the date gets closer, it will pop up. members send back tickets and they go on general sale. I read recently about 30,000 tickets are on sale 48 hours before the game. So even if you go without tickets and go up to the stadium early in the day of the game. You WILL get a ticket.
Here's the thing; it's virtually impossible to get a Clasico ticket but I was looking at their price brackets and the whole fucking A++ thing is stupid. Granada tickets are quite cheap but I don't really want to go and see Barca roll over some team and it not be entertaining if you know what I mean? I almost suggested to our parents couldn't we go Valencia where the weather's a bit nicer and they'll give Barca a game?