I'm taking a plane where should i get my duty free products ?

I'm taking a plane from Singapore to Milan, Where should i get my duty free alcohol is the prices of alcohol cheaper in the duty free in Singapore or Milan ? Should i buy my Baileys here or there ?|||You should get them in Milan cause there's more options and it should be relatively cheaper.|||Note the price here before you leave, and then compare the prices there, and if they're higher, then wait till you come back to buy.|||I'd just buy it on the way home that way you don't have to carry it through out your trip.