That was a price CBS apparently met for Lord with HAWAII 5-0, cuz the guy supposedly wound up owning a hunk of the state by the time the series ended.
Desilu wasn't CBS. When Herb Solow was brought in to revitalize Desilu's television production they couldn't afford to deal away that much of any series' they were looking to produce. The reputation of the studio at that time was known in Hollywood and Jack Lord was a shrewd businessman, therefore, it would be much more of a stretch to think he didn't know the studio was incapable of giving such a deal as he was demanding than to assume he did.
CBS, on the other hand, had pioneered helping stars setup their own production companies (and giving them half ownership of their series) as away to help them shelter income from the high tax rates of the day. This was how they were able to raid NBC's talent roster about 10-12 years earlier when they grabbed Jack Benny among others. It was also how they got David Letterman in 1990 (and why, even though Leno is #1 in the ratings, Letterman has the much larger bank account).