It's hard to say. You can get a good breakfast for a few quid, but a dinner will cost you a bit more. It just depends on what you eat and where you go to eat it.

I agree, it depends where you are staying too, you can go all cheap and cheerful or go up market....let us know where in Alcudia you are staying and no doubt there will be a fair few suggestions for where to eat!

You can have an excellent three-course lunch with wine for under 10 euros. Look out for the 'Menu del dia', especially in restaurants where the majority of diners are Mallorcian. There are many tourist-orientated eateries, some excellent, others dreadful, but in general the quality / value offered by those near the beaches is less good unless you enjoy chips with everything.