In 2002 we booked the Celebrity Millennium. We'd sailed on Mariner the year before so I tried to make it a comparable experience and booked a jr suite with a verandah. By the time we added wine with dinner, soft drinks and whatever it took to be equal and compared the final bill, we came within a few hundred dollars. ..
This summer when I took the kids on the weekend cruise in adjoining 119 sq ft staterooms on RCCL, my cost was actually over $220 per person per day - hardly a RSSC Experience. My SAND costs were just over that - Fare only. If you look for the right itinerary on RSSC you can actually pay about the same!