Anybody thinking of retiring to Spain (especially those from the UK who appear to me to be the most naive on Earth) should think fairly extensively. Fortunately, this is not too difficult. Let's say you've decided to move, not selling your UK home, not seeking employment, not bringing kids.
Do not forget repeat do not forget that on the Costas you are in Renters Heaven. Supply is outstripping Demand. You can decide to rent in different apartments on the same road forever. If you've got an iota of sense rent privately. Out of season a well located, good 2 bedroom apartment will fetch around €550 per month in rental. Electricity costs will be in addition to rental.
I have seen retired couples being screwed bareback by some real estate agents regarding finders fees, commission, advance rental, deposit against damage, deposits against the sun shining etc.
And your average naive, please screw me retired Brit thinking he (usually a he) is looking a gift horse nearly always bites the bait.
In Ireland we have a saying that faraway fields are green. Fields are less green in Spain, but Mr "I can't wait to move to Spain" in his vaguely thought-out anticipation, leaves what's left of his brain back in Blighty. In whatever location you choose to live it should take no less than five seconds to discover that hordes of rentals are immediately available.
But, if you're the guy who enjoys waiting in queues, thinks every day is a jolly one and England will win the World Cup, The Daily Telegraph is the be-all-and-end-all of good newspapers and every Brit in Spain is honest, then lie down and prepared to be trod on and you deserve no less.
For everybody else, keep an open mind, always rent with the possibility of a retreat in mind. Be honest with yourself and enjoy the sunshine.