Hello TwoSix and welcome to cruise chat;
penny3333 gave you a good overview of the cost of wine and drinks.
I'm not too familiar with Regent Seven Seas cruises or the Paul Gauguin except by reputation, which by the way, is excellent, so I did a little checking; and depending on what catagory cabin you are thinking about, I saw some prices for Paul Gauguin that were not much more than Tahitian Princess; and factoring in the things that are included I could conclude the Paul Gauguin was actually a better deal--and this from a die-hard Princess fan.
Some sailings and cabin catagories were astronomic, but there were also some that seemed quite reasonable--as low as $1995 for 7 days.
You might want to check a little further.