Whenever we're in Ezeiza I always browse the duty free or, as they euphemistically call it here, free shop. I've never found the prices to beat what you can get in a Chinese or some of the special offers in supermarkets. In fact, the same could be said for UK duty free, to a lesser extent.
On the ferry back from Colonia we spent a while in the free shop and frankly, the prices are a joke. Jameson whisky for example is US$24 and I can buy the same in the Chinese for about AR$900. The same applies to most of the other stuff, but we did buy three Toblerone packs as gifts for a round US$12, I think, because Adri has some change left over.
I felt very poor actually
Anyway, here are a few shots of what was on offer.