Wine package on board or duty free wine in port??

Hi everyone we are on Arcadia Sydney to Soton in Feb, and just wondering if we can actually buy duty free wine in port duty free shops in places like Singapore, Mumbai, Colombo and Dubai? If so can anyone give us a comparison of prices between duty free wine and on board purchased wine.

Thank you in advance for any information you can give us,

Wendy and David

In most places you cannot purchase duty free wine and then take it back onto the ship. You will find that wine will be very costly in places such as Dubai.

Keith