When you bring up a specific flight on ITA, click on "show booking details" in the top right, it will give a break-down of all the extra fees and taxes. You can check if the departure fee is included in the price. Can be quite interesting what you're paying for. ITA is usually pretty good about including all fees, though sometimes they miss things like new fuel charges. Also, depending on the country, some places still have a 'pay at the airport' departure tax, though this is becoming more rare.

---Lawnboy