I agree with the groupings of the cruise lines. Luxury is your Silver Seas, Regent and in between the higher end big ships like HAL and the Luxury is Oceania, Azamara etc. you need to compare apples to apples. For a similar itinerary and room, age of ship and just compare base price, wonder which of X, HAL, PCL is cheapest? I think X is the higher of the 3.