We paid about 7 euro I think to go to the top of the wall. It was a fairly long walk couple hours with photo stops. If you don't mind walking? The view was well worth it.
I was a bit disappointed because due to the volcanic activity the Adriatic water was a bit rougher than usual and the caves were too dangerous to enter. So we had to give up on our plans of kayaking along the crystal clear waters of the Dalmatian Coast line. However, we would not have had a chance to explore the beautiful city and would have missed out on what Dubrovnik has to offer. Everything happens for a reason!