You could try http://www.kelkoo.es/. This site is the mirror of the kelkoo UK site and lists lots of on-line electrical (and other) retailers, with usually the lowest price for any individual item and options on delivery etc. There’s also http://www.euronics.es/, which has a network of electrical retailers throughout Spain - they’re very cheap but the range is not comprehensive. In my experience kitchen stuff is cheaper in Spain than the UK, while home entertainment and computers are more expensive. Some things which are more important in a hot climate - air-con, fans, plug-in radiators for houses without central heating - are much cheaper in Spain, about half the cost. Some older televisions from the UK won’t work with the Spanish system, but DVDs etc. should be fine. Plug adaptors are about a euro each in a supermarket or the fereteria, and you can get them in B&Q in the UK for not much more.