hi emmaki,
as you are a EU citizen, then, provided you have been resident in the EU for the last three years, you will pay home fees, not overseas fees.
however the amount varies per university and within universities, per subject. so the only thing to do is check out the universities/courses you are interested in, there should be information on their homepages. i am currently paying ca. £3200.- per year but as i said, that might vary considerably.
don't forget to consider the living costs. london is very expensive, outside of london it is considerably cheaper to live.