If you've built up a lot of Ship XP, it's always good to know what it may cost to convert it to Free XP depending on the situation.
Listed below is comparing costs from the quantity of Doubloons you may have purchased (at certain purchasing levels) and the exchange rate it will cost converting the Ship XP towards Free XP.
Of course, Doubloons will go on sale at times and the regular costs could even change (hopefully not higher).