$1500 tops for 25 people in 1978, with lunch at a nice restaurant and including renting the hall and the Ethical Culture Society guy who married us, and a “rehearsal” dinner for everyone who attended the wedding and was there. It might have been less - it was well within budget. It was also the biggest wedding that anyone in three generations of our families had.
That’s $4,000 - $6,000 in todays dollars, depending on how you calculate the relative value of a dollar. But using the Consumer Price Index, it is equivalent to $4900.