"We're concerned that the fees for the business side of things, for the cultivation centers, for the dispensaries that those are going to be so significant that the investors for those businesses are going to want a return on those investments," Linn said.

Under the state's rules, a cultivation center would be charged $25,000 just to apply for a permit and $200,000 to receive the permit if approved. Each year, the dispensary would have to pay an additional $100,000 to renew the permit.

"We're happy that they have the fees set so there's going to be professional people involved in the cultivation and the dispensing," Linn said. "But eventually, all that's going to be trickled down to the patients, and we don't want rich people getting richer on the backs of sick people."

Linn added that increased costs could contribute to a continued black market for marijuana in the state.

"If the price of medicine through the program is 10 percent or 15 percent higher than the street price, we're going to see a lot of non-compliance," he said. "If it's a cost burden, they're going to continue going to the illegal market, and that could undermine the whole program."