I'm sure cruise lines track spending versus the cabin category booked, including when and how the cabin was booked, so they know the statistics. Lacking their data it's hard to draw anything other than a generalization, which typically degenerates into a debate, about who spends more or less. Again a generalization but on the surface it would seem that regardless of the cabin category the more experienced and frequent cruisers probably spend less on average than the "trip of a lifetime" type passenger.