That's around what roadshow tickets cost in DC at the time, about half-again to twice the price of "regular" engagements. Roadshow tickets were actually pricey, given that those evening tickets downstairs would be over $23 in today's dollars.
Just checking it out on my projector and this version indeed looks far better than the Olive Blu-Ray. Looks like MGM actually did a new transfer. Maybe they will now do the same with THE GREATEST STORY EVER TOLD, another Ultra Panavision 70mm film which looks terrible on Blu-Ray.