I do not recall what the HIA cost. $99 seems low.
Looking at this cruise now, the difference between Inside and Verandah (we got a partially obstructed one) is $500.
Add in the $200/person OBC that you pay upfront....taxes, and the HIA...it came to $1,189 p/p.
$500+$200+$140 (taxes)+ $349 (difference, likely cost of HIA) = $1,189.
We consider this a great bargain since we love the Koningsdam and it takes us 7 minutes to get to the cruise terminal.