From the 2019 BH Photo article whose link I posted above:
"Cost has long been a factor in the acquisition of an OM projector. The Zeiss Model II cost $75,000 in 1926—more than $1 million in today’s dollars. Modern OM projectors can cost well over $2 million."
A 2011 Sky and Telescope article about Boston's Planetarium says, "Costing $2 million, the Zeiss Starmaster installed at Boston's Charles Hayden Planetarium uses fiber optics and its lens-covered 30-inch ball to project up to 9,100 stars."
