I did my PPL in Barcelona Flight School, I am still a membership (Aeroclub Barcelona - Sabadell). Now I am studying ATPLs with Bristol Groundschool and I based my decision in quality instead of price. You can do your PPL in Barcelona and then go to a high quality school like Professinal Air Training (Bournemouth), Airways Flight Training (Exeter) or Bartolini Air! You can train modular with a very good standards of training with half a cost and include a FI rating. Obviously all the school will said to you that you can not train in diferente countries but they are lying! From all of the above, the most important thing is to decide which country you want as a State of Licence Issue because remember that the country that hold your medical is the country which has to issue you the licence which means that if u have Spanish PPL with an EASA class 1 and 2 medical and then you want a UK licence u will have to convert it (and its ... Process, I did it)!
Cheers!