The port fee (which is in tiny tiny type under the pink-sand picture) is a fixed amount, $162.37.
The other taxes & fees are variable depending on what cabin you book, how many are in the cabin, and so forth.
$279.70/pp is the sum of all of the taxes & fees (excluding the Free at Sea gratuities.) They can't show you that number until they know all the variables I mention in the second line.
To clarify: Read the pink-sand-picture information as "Now starting at 299, plus taxes, plus fees, plus port fee of 162" or something along those lines. Is it deceptive, or merely ambiguous? Your call, but it's pretty typical of fine-print shenanigans everywhere {shrug}