But the sales of toys, video games, clothing and books in more than 100 countries have earned nearly six times as much in that time.
Mr Roffman said: "This is something that has stood the test of time. It made a huge impact on the culture when it was released.
"It was a mythological story that delved deep into the things that affect us as people - and it stuck.
"What we found is not only is it significant for the original generation that saw it, but those people when they had children wanted to introduce their children to it.
"And it resonated with their children just as much as it did with them."
He continued: "George was a student of mythology and he structured these stories to capitalise on the archetypes of mythological characters and the story elements of heroic quests.
"There are so many parallels to political life, to artistic life to cultural life - it's an interesting point of study."
When asked whether merchandising lessons had been learnt from other major companies like Disney, Mr Roffman said: "Certainly their long-term management of their brands has been an important lesson.
"But there are also such significant differences between what Star Wars is and what the Disney properties are that we've tried to be really careful to not try to imitate others in what we do."
Whilst Hans Solo was recently voted the most popular character in the series, Darth Vader merchandise has been the highest selling.
Mr Roffman said: "He is very iconic - one of the greatest villains of all time.
"But as the story unfolded he was also an immensely complicated character, he wasn't just pure evil - he was somebody who started out good.
"And I think that's one of the reasons it resonates so deeply."
Mr Roffman also spoke about a new animated series - led by Lucas - which will parody the Star Wars plot and which will premiere next year.
He said: "Star Wars is so iconic, that we can have fun with the property, we can laugh at it.
"George Lucas has always embraced that dichotomy from the very beginning - he loved the parodies that were done but, when it comes to telling the Star Wars story, it's serious business for him. So he can embrace both sides."
Mr Roffman was confident about the brand's future.
"We've seen that Star Wars is kind of a renewable resource. There are still so many stories to tell. I think this will go on for a long time."