To confirm, these are the DIFFERENCES in prices between the 2 packages, correct? If the classic drink package (which is included) is $69 pd/pp, and Premium is $84, you pay the $15 + 20% = $18 pp/pd for the upgrade? For 2 people this would be a $252 upgrade on top of the All-Included Fare.
I assume this is the same going from the Basic Wifi to Premium - you pay the difference?