If your flight was delayed by more than 3 hours, you are entitled by EU law (Regulation 261/2004) to claim from the airline depending on the distance of your flight. In the case of flights over 3,500km (outside the EU), the airline is eligible to apply a 50% flat reduction on compensation awarded if the delay was between 3 and 4 hours, if the delay was greater than 4 hours they will be liable to pay the full €600. The amount you receive is irrespective of your ticket cost and is set by EU Regulation 261/2004.
†Your claim will be settled at the Euro equivalent on the exchange rate at the time of the delay, or on the date your claim is settled (This will depend on the airline). ‡Between an EU and a non-EU airport.