We started running a comparison just to see what our actual cost would be in comparison to the Silversea or Seabourn crossings during the same time frame and they all come out about the same.

Oceania cruise only rate (after B&K discount and figuring about $800 credit for air) $1044 on 11 day cruise 215 sq ft cabin = $95 per diem

plus other per day charges on Oceania
gratuities = $11.50
4 drinks = $36
4 bottled waters or sodas = $11
bottle of wine (split) with dinner = $21
bottle of champagne in the evening (split) = $26

Actual per diem about $200 per day on Oceania.

Silversea 14 day crossing. $2601 (after B&K discount) = $185 per diem (a little weighted because we get the Venetian discount and the onboard discount)

Seabourn 12 day crossing. $2373 (after B&K discount) = $197 per diem