I’m not an expert but having visited the island for the last ten years I’ve see property prices go through the roof. In many respects the market reminds me of London, i.e. expensive, and it doesn’t look like it’s going to cooling down any time soon.
However Ibiza is a beautiful, interesting island that offers so much more than most Brits expect – big clubs, package holidays, San An and worse. And with the Baleric government and private investors currently pouring money into the island (building a new marina, road system, 5 star hotels), they obviously believe that the party’s not over yet.
I guess I’m biased and not very business focussed as I’m currently trying to buy my first property on the island, sadly not quite in your league (more in the line of two bedrooms with a roof terrace). However I’d say go on, take a chance on the white isle – you might just enjoy it!