Prices are impacted by many other factors than the currency used - perhaps most importantly taxes.
When corrected for VAT rates, the US price becomes more like 1200 * 1,23 = 1476 USD.
The true difference when VAT is taken into account is about 200 USD. Noticable, but not a tremendous difference, given that the cost of doing business per customer in Poland is most likely higher than in the US for Apple. (The US is their home field, after all...)
I'm guessing they must also pay some sort of import taxes to get their products in the EU?