re: Cruise extra costs question

You drink beer or booze? If booze, buy some rumrunner flasks. I've used them on 3 cruises and have a 100% success rate. Put them in your checked bag....I've brought multiple fifths on each cruise and only end up buying a couple of drinks.

I've always prepaid the tips.

Excursions have cost me the most, but it depends on what you want to do. Where are you going? We did some badass excursions in Alaska that cost a good bit but were totally worth it.