Another outfit in Spain is called "Fly in Spain" - a regular here has some connection there. There are several threads about it.
PS I second every word above about "cheap" - "cost-effective" might be better to go by, and is probably what you actually meant.
PPSS are you sure it is a PPL you want? If you would consider flying a microlight, there's an Englishman in Portugal's Algarve offering exactly what you are after. Would certainly be less expensive than a PPL, and Portugal is a more enjoyable country than Spain, for foreigners, by all accounts.
PPPSSS are you sure it is a "school" you are after? IF you have good French (and that's a big if!) you could consider the summer classes offered by certain French aeroclubs - one example can be found at
http://www.aquitaine-hydravions.fr/ (they do landplanes, too).