In 1967 this cost 12,000,000.00 How,Why?

Just by spending,and spending, and spending and charging all the costs to the movie, even if those costs have nothing to do with the movie whatsoever. Basically, my guess is it all went to paychecks and the all-star cast per diems, because the film looks cheap. The sets look like TV sets, the dollars are certainly not up there on the screen.
As an example, they kept Woody Allen waiting for weeks and weeks in an expensive London hotel with nothing to do. He wrote "Play it again, Sam". Of course they were paying him all that time for doing nothing.
The normal procedure would have been to have an schedule to shoot the scenes, like "Woody Allen shoots from 2nd april 1966 until 15th april 1966", and book hotels and flights accordingly. That was just Woody. Now multiply by all the stars, directors, star-directors,writers,...

An all-star cast and a bunch of star bit roles and cameos can be very expensive, as you're not only paying a ton of big-name actors, you're also paying to put their entourages up in 5-star hotels.

And location shooting.