After spending some time in the South for college, I know how difficult it can be to find discounted flights out of the country. Charlotte and Atlanta don't even remotely have the same type of deals that I could find out of New York City, Boston and Los Angeles.
Today on Kayak.com, I found several roundtrip flights in the $663-$668 range from Charlotte to Madrid, Spain on Lufthansa Airlines. This fare includes all applicable taxes and fees. Flights depart September 3, 2014 and return September 22, 2014.
Two of the flight options are displayed below. Note the travel-time in the second image is 31 hours. This particular flight includes a 19 hour layover in Munich, Germany.
Trusted Travel Girl Tip: Long lay-overs are an excellent way to enjoy a short visit in another city or country on your way home. Make sure if you choose to take this approach while traveling, to check your luggage or pack light. Additionally, have a plan! Be sure to do your research on how far the airport is from the city-center, and what is most important for you to experience while there. An excellent airport to try this in for the first time is Amsterdam, Netherlands.