Basically prior to the being sold the paper was profitable every year except the last year. Then in 1976 Murdoch bought. I put an excerpt that explains the market challenges of running the paper. Despite these market challenges he ran it for a long time at a loss. It’s my opinion that the purpose of owning the paper which loses money every year is influence and power, not just numbers on a balance sheet. That’s why Murdoch ran it at a loss for so long. Likely he believed the influence and power netted more money for him overall.

The article says:

The Post at this point was the only surviving afternoon daily in New York City and its circulation under Schiff had grown by two-thirds, particularly after the failure of the competing World Journal Tribune; however, the rising cost of operating an afternoon daily in a city with worsening daytime traffic congestion, combined with mounting competition from expanded local radio and TV news cut into the Post’s profitability, though it made money from 1949 until Schiff’s final year of ownership, when it lost $500,000.

When you own a newspaper you can do things like this: https://www.dailydot.com/debug/new-york-post-writer-resigns-kamala-harris-book-story/