Grimbo....I know what you mean regarding costs. Everyone seems to charge double (plus some) for high season travel and pitches. Also, it is such a long haul down to Spain for around a Three week stay. To be honest I would not do it for such a short trip, but I suppose needs must...
In comparison, we went to the Costa Blanca, south of Alicanti, in early March and stayed until the end of May (87 days). The Ferry, (Portsmouth/Bilbao), campsite fees and Diesel came in total to