Question : What is the cheapest day to fly in the next four weeks?
Answer : Since low prices are preferred, look at Mar 9th. As of Feb 20th, it's showing the cheapest ticket sales at $4,156. That is 3% below the average price for this route, so you can spend that extra cash on a fun experience in Lisbon.
Question : Do prices fluctuate more for this route than others?
Answer : Flight prices fluctuate much more than most routes from the United States for GSO to LIS. They range anywhere from $1,062 to $4,403. Prices tend to be lower the further out you book.
Question : How long do most people visit Lisbon?
Answer : Of course you're not most people, but if you were, you'd stay roughly one week.
Question : Is price more important than specific travel days for you?
Answer : The best day to fly on a budget this month is Thursday. Having flexibility in your travel plans means you can save more, so be sure to plan ahead when possible.