iīm so sad that i havenīt seen your post before!!!!!!!!
I donīt know how can anyone recomended Arpi or Casanova for developing anything!!! JESUSCHRIST!!!
I lived in Barcelona 10 years and i still have many contacts and friends there.
My first recomendation for a good Lab is EGM they are more or less the best lab in Spain, they are used to deal with professionals and you can ask for anything, if things havenīt change past months they are the only lab that stills develop E6 around Barcelona. For Black and white i donīt know if they still do it (i guess so) but in that case you have COPIA (the one you have mention in Gracia) the one and only true black and white lab around. I am not a huge fan, in fact they have that attiude that if you are not a common client your work will not have special attention if you know what i mean, but i have never see a bad or damage negative or print from them, when i was there they were using xtol all the way.
If still you find them quite expensive there is a special trick, you can go to primer plano, they are a small lab but nice people the good thing is they send all E6 to EGM and all BW to COPIA, and itīs cheaper than go yourself to the other labs!!, the only drawback is you lose direct contact with who is gonna develop your stuff but that for bulletproof stuff doesnīt matter that much. In your case i will go directly. But never ever go again to camera shops to develop anything!!!
There is more labs around, some are good, some are shit, some must be closing down now, but if you need to know anything more contact me!
btw. if you need to buy film you will see there arenīt great options in Barcelona, all i can say is that i was buying from germany or usa since 5 years ago, but in case you need few rolls go to Casanova, at premium price of course!