I am contemplating an Oceania cruise for 2007 Baltics - just in the idea of comparing and planning stages. If we are taking this on RSSC then I would want to book on-board during WAVE.
So far - adjusting the pricing to account for Tips and chit signed items for us, same itineary - but on R - 3 days shorter - both have free air. Tip credit by TA so included, smaller room on O (E Category) adjusting again by SSS and an onboard price booking, the Per Diem for RSSC (Category G) is $525 pp per day and O is $328.
Now I am comparing apples and oranges but have done much to make it even. If I booked a Concierge Class on O - it would be much closer in price, but, since I am sneaking this one into the travel plans, just those few thousand could mean missing this itinerary for this particular year.