The most recent
inflation adjusted list I've seen puts S:TM at $367,092,000, which is based on an average ticket price of $6.40 for 2006. But S:TM unspooled in 1978. Those were the days of platform releases, where a film would take upwards of a year to make its way around the country. At its widest release, S:TM was only in 817 theaters nationwide, and had a limited opening for a then remarkable 508 theaters. Today's blockbuster films get saturation releases and are expected to meet or exceed their production budgets in the first two weeks of release, if not sooner LOL.
It's hard to make comparisons with older films, particularly ones as old as S:TM. Most people had no idea what a video cassette recorder was in 1978, much less own one (Sony's Betamax hit the streets in 1976 followed shortly by RCA's VHS in 1977.) The big three broadcast networks had a 91% share of prime time audiences during the 1978/9 season, and "cable" was something you used when the antenna on the roof didn't work. Computers and the Internet were not in the common lexicon outside of science fiction stories, and "Space Invaders" was the latest popular video game at the time. People were still playing "Pong" in 1978. LOL
So what did people do for entertainment back then? Well a LOT of folks went to the movies. It's different now. Very, very different.