This one's especially for first-time cruisers, the people who always ask someone like us how much the cruise will cost over and above the fare.
The answer: "As much as you want."
If that sounds like a cop-out, it's not. The so-called hidden costs of cruising are almost all a matter of choice. The two that give you no choice are taxes and gratuities. Neither is included in the price that you shop for when you go looking for a cruise.
Taxes seem to depend on the departure port and, to give you a ballpark figure, generally run between $150 and $200 per person for a one-week cruise. Gratuities vary by cruise line but using $11 or $12 per day, per person, will cause you no surprise.
After that, you pick and choose.
Shore excursions can go from $30 or $40 to many hundreds, which is what you can expect to get on a small plane to look down on Alaska or land on a glacier. The other side of that is to walk ashore and do your own thing, using local transportation. In between are the "shore excursions" you can purchase on the shore.
Then there's drinking, and that doesn't mean just booze. Drink packages are available, depending on how many bottles of wine or pina coladas you anticipate consuming. There are also drink packages for soda pop, which is not free. What is free are things like fruit juices, iced tea and coffee (but not specialty coffees).
Food can be another biggie. With the influx of specialty restaurants — if you choose — you will pay $15 to $40 per person for an upscale menu and experience. On the other hand, every dining room we've been in on ships has been good to excellent…and included.
Entertainment? Some cruise lines charge for some shows, but there is often lots available with no extra charge. Bingo, bowling and casinos all come with a price tag and in most cases it will be more than you expect. However, there is lots to do on ships without paying more…lectures, cards and backgammon, a library of books.
As for being pampered, fitness classes and hair dressing and massages will cost what they cost you on land and probably more. But that's a choice. So is shopping, but isn't it always? So is the Internet. While it's getting cheaper, checking email can be a frustrating and costly venture (or ad-venture) at sea.
And if you buy those annoying photo ops getting on and off and staying on the ship, you can spend a small fortune. Or you can make your own pictures by asking a stranger to use your camera.
One estimate we've seen is that cruisers can spend an extra $200 or $300 per day, per person, on a cruise. We've never come remotely close to that, mainly because we've always tried to balance what we do and don't do.
Just like in life on land.

Norwegian Star
9 nights
June 30, 2013
Copenhagen (return): Berlin, Tallinn, St. Petersburg, Helsinki, Stockholm
Inside: $399
Cost per day: $44
www.ncl.com