We don't take cash with us at all - there are loads of ATMs on the Balearic Islands and so all you need to do is go to a hole in the wall. Much safer than carrying cash, especally if you are going to crowded place!
I have a holiday account with the Nationwide BS as they (currently) make no charge for foreign withdrawals, whereas most of the other banks charge you about £3 for the privilege.
Can't help with prices but breakfast was about £6 last time I went.