I think it's transport costs, tariffs, but perhaps most of all pricing strategy from the producer or importer; positioning of a product in one place can be made "luxury" and being priced for max profit, while in the other, where there is a huge market share, the product is priced for maximum quantity.

I wonder if there’s some quality difference between those products. 

If not, I guess it’s just due to it being a relatively low unit value good, which makes it harder to arbitrage across large geographies. 

Although, there are also service costs embedded in those prices and those would require PPP adjustments.

Undisciplined

I was also wondering about pet food - the cost of a can of branded food from Mars Food or Nestle (like Purina) is very different across countries (I know because once upon a time we had a traveling cat with us.) I.e. in Germany a can would cost $0.50, in Turkey you'd pay $1.50 for the same can. The "pampering" from the cat's perspective didn't change, but the expense definitely did.