Learn Italian: Il prezzo è in dollari, non in euro. - The price is in dollars, not in euros.

In Italian, the word euro is invariable, meaning its ending doesn't change in the plural. You say un euro (one euro) and cento euro (one hundred euros). However, dollaro is a regular masculine noun, so it changes normally to dollari in the plural.

Could I say Il prezzo è nei dollari?

No, you shouldn't use the combined preposition (like nei) here. When talking about the currency used for a price, you just use the simple preposition in, exactly like saying 'in dollars' in English.

What is the difference between prezzo and costo?

Both words are related to money, but prezzo refers specifically to the 'price' a customer pays to buy an item. Costo translates to 'cost' and is often used for expenses, the cost of making something, or the cost of living.

How do Italians pronounce euro?

English speakers often say 'you-ro', but in Italian, it doesn't have a 'y' sound. You pronounce it by blending the Italian vowels 'e' and 'u': it sounds like 'eh-oo-ro', with the stress on the first letter.