My wife and just returned from a cruise on the Costa Fortuna to the Greek Islands. Overall it was an enjoyable cruise. The ship is clean and our cabin was very nice. The stewards were excellent and pleasant. It was definitely worth the price.
However ...
Costa Fortuna could cost a fortuna. The excursions were so ridiculously overpriced that we skipped all of them on principle. We learned on the excursion to Bari, which is marginally worth seeing, that the ship was pushing organized excursions as a major cost center. Paying essentially $100 per person for a bus ride was, well, let's say, overpriced. Walking around the old city for free cost nothing.