TrvlPro,
somehow I agree with you, somehow I don't.
I understand that lines expect a certain revenue from the service(s) they offer.
Neither I'm surprised by their thinking of material gain (that's what we all do in our job).
On the other hand, I don't fully agree on the selling strategies: "the main service costs x (low), the additonal services cost y (high)".
We all know pictures, booze and all the other stuff cost much more on board: you should say, "of course they do, due to expensive delivering, loading, and so on".
But what about food and all that's included in a cruise fare? Don't all these things need to be delivered, loaded, etc. on the same ship? They do, but their cost is "low".
So, seems to me e.g. like buying a cell phone for some Eurocents (sure this happens in Italy and Germany) finding then themselves tied in expensive calling fares.
But ... the cruise fare is in any case "low"

, and even if they hope you'll spend many bucks in additional services you're not forced to waste money.
Don't get me wrong, I mean "waste".
Indeed, cruising with a locked wallet isn't a vacation.
It's a punishment.