You tube that shiit
Depending on the teacher anything from 8 quid to 20 quid an hour. You need an instrument to practice on which is another expense but the instrument itself is really quite simple to learn provided you are willing to practice. There are a LOT of books available for learners and it is a very rewarding instrument to learn.
Me too, I'm eternally grateful to my mother for making me keep going to lessons when I was a kid despite my teenage stage laziness :)
"how much it is and is it difficult to learn?"
Do you really want to learn? Piano is awesome and worth it. Do it, Invest your time.
My mom taught me so I don't know price. The level of difficulty depends upon the student. Some pick it up fast, others don't. Although I'm a fast learner, my lack of coordination limited me.
I thought it was a lot easier than learning guitar. I don't remember how much it is though, but it's not super hard. Very doable.