Sure. What were your expectations on price? Last year I bought excellent Clasico tickets for 400 CHF each. There are 3 ways really:
1) Through a club member directly - either you pay the face value (A pittance really and very unlikely) or you pay a premium. It comes with a caveat however as the club is cracking down on resale of season tickets at a profit (They want to ensure they get their cut which leads to option 2) and you do run the risk that at the gate you will need to verify your ID to match that of the season ticket - this is particularly checked for the big matches & none are bigger than El Clasico. It can not only see you prevented from entering & losing the money you paid for it but also the season ticket holder runs the risk of having their season tickets revoked (A big deal). Still, I have taken this option several times through a local friend but perhaps to already looking a bit Catalan (Pep, in fact
) I have never had an issue but the risk is real. Also, I have stopped using this approach for the same reasons.
2) Ticket pool through the club website - club members who opt out of using their ticket for this match can have them put into a resale pool sold by the club via the same portal you buy tickets in general. They are normally released to the public for sale after a certain period of time ahead of the particular match (Sorry, I don't recall the time frame but it can be 6-8 weeks before the match - so you won't see them available now for example).
3) Ticket resalers - again, at a premium (The highest premium among the 3 options) via a number of 3rd party sites
The tickets themselves (Officially) come as an email/pdf. You can download it to your phone and they scan it or print it out.
Option 4 which I didn't include is basically showing up on the day or two ahead of the match and finding sellers around Camp Nou, of which you are assured will be there for
any match. Can be risky albeit the cheapest option as you can be sold a duplicate ticket that will not allow you to enter once scanned. Even if you happen to enter the stadium first, the legitimate ticket owner who is denied entry due to the scan signalling an earlier entry, sentries will come to your seat and remove you
All the matches are great to attend but has to be said El Clasico has a different vibe/atmosphere
My advice, get the best seats possible as you will probably not do it again