Paint would save grams, all things being equal. Would they design the core/cover to be a few grams heavier than normal to allow for that, or go with an ever so slightly lighter, smaller ball?In this instance, paint would be a couple of grams probably at the most. It could also impact the diameter of the golf ball marginally.
Being a smaller seller in the space and only a single product line extension it wouldn't do a ton for shipping costs, although i your world I could see it making a huge difference.