I am about to PCS back to the states from Germany. I have already been to Barcelona and Valencia during the La Tomatina fest. I want to go to Spain once more before I leave. I have friends going to Barcelona but I also have friends that want to go to Ibiza. Which should I do and why? Also note that both are pretty similar in what I want to do, except Ibiza may be more expensive and is an island.

TL;DR Ibiza or Barcelona