I see the basketball situation a little different though. Donnie is set to make around $2 million this year. Season ticket prices start at around $100. Teams like Loserville and Kentucky charge upward of $40 per home game ($600 and up for season tickets) and have a waiting list of people willing to pay that and more. SMU's attendance doubled the 1st year with Larry Brown ($2.8 million) from 2K to 4K and reached 6K in his second year (7K seat arena)... oh, and they nearly doubled ticket prices to compensate for Brown's salary at the same time.
If you put a product on the court that people will pay to see, you can raise prices to compensate salary. Current season ticket prices (around $100+) average out to less than $10 per game for the cheap seats. With a roughly 10K seat arena, every $100 increase in season ticket price covers $1 million. So, increasing season ticket prices to $300 would give an extra $2 million on top of what DJ already makes ($2 million). Now, you can afford a $4 million coach. If you reach Loserville levels ($600 tickets), you have your Calipari salary.
General rule of business... You have to spend money to make money.