It is import to remember that in Spain, like many other countries, the manager of a bank can exercise judgement on what each customer is charged for any service. It is therefore most important, in addition Acer’s advice, to negotiate with any bank you think will be OK for you, before you open an account. Other customers' experiences with a bank will probably have no bearing on how any other customer will be treated.
An example. Most bank charge a percentage when funds are transferred into an account from say UK. My son spoke to his (my) bank when he bought his first property here, and he pays 0.30 euros as a flat rate charge on any transfer received. It saved a good deal each time he transferred cash, in Euros, from UK to buy a property.
Also,, do not think that anything here is the same as in UK (or anywhere else) it frequently is very different, so always ask before you act if you do not want nasty surprises.
Sol Bank , now part of Sabadell, charged me 0.5% on the whole of a sterling investment transfer to another bank. It amounted to £800. In UK that would probably have been a max of £25. I got stuck with that charge even though I knew the system and tried very hard to negotiate with the bank. I was closing the account so they were, shall I say, not 'helpful'.