I also think massage prices have gotten out of hand - and salon. I would not pay or buy anything special for a formal night on a mainstrem cruise ship anymore (unless it has other uses) because they just are not that formal anymore.
But as someone said - how about cutting back before you get to the ship.
You will not get a meal like Sambas on land for as little as $20 per person. So skip the fine dining at home a few times before the cruise.