The No. 1 question among medical marijuana cardholders is: Why is the state making so much money off them?

Some cardholders have gone to court, asking a judge to force the state to lower the fees it charges for them to receive their “green card.”

Will Humble wrote the rules for Arizona’s medical marijuana program after voters approved it in 2010.

“I made some mistakes, and these are the mistakes that I made. I'm not perfect, but all in all it's a pretty good program.”

The former Arizona health services director said he underestimated the number of cardholders when the $150 card fee was set.

“In the end, we have far more patients than I anticipated and therefore more revenue,” Humble said.

Now medical marijuana users are going to court to force the state to lower the card fees. Their lawyer claims the state "knows that it is overcharging its sick citizens, yet it does not provide any services with these excess funds."

Here's how much money Arizona is banking from the sale of medical marijuana cards:

-143,000 Arizonans pay $150 a year for a card
-In the last year, the state collected almost $25 million

But running the medical marijuana program cost only $11.2 million, so Arizona turned a profit of $13.7 million. The total profit on medical marijuana cards over the last several years is $38.1 million.

“I had intended to make fees we could operate the program, have a little bit of cushion because you never know when you're going to get sued or something extraordinary is going to happen,” Humble said.

The state's medical marijuana law gives health services director Cara Christ the power to spend that $38 million stash.

The state does charge cardholders far more than is needed to run the medical marijuana program.

But a judge will decide if that's legal.