A Financial Impact Estimating Conference report concluded Monday that the cost of medical marijuana in Florida could not be determined due to uncertainty regarding taxation of the plant.

Although the Department of Health estimates the annual cost for Florida would be roughly $1 million, the FIEC report would be more-accurate if marijuana sales taxes were clear.

"The extent to which medical marijuana would be tax-exempt is unclear without legislative or state administrative action," the report said.

Amy Baker, coordinator of the Office of Economic and Demographic Research, said there will be at least an agricultural tax exemption for medical marijuana. It would allow a grower to sell directly to a user tax-free, but if a third party is involved the end user would be taxed. Possible exemptions for food or common home remedies will need a legislative or state decision.

Other states have seen large revenues from taxes on medical marijuana. In 2012, Colorado's medical-marijuana tax revenues came in just under $6 million, even with a population nearly four times smaller than Florida's.

The FIEC report says "fees will cover at least a portion of the regulatory cost" of medical marijuana. According to the Department of Agriculture and Consumer Services, there would be fees for growing operations of two or more acres. Other agencies have said increased regulatory costs could be offset by more fees.

The report was brought on by a possible constitutional amendment that would allow the sale of medicinal marijuana. Attorney General Pam Bondi is challenging the amendment, arguing its language is misleading.

Florida's Supreme Court will hear arguments Dec. 5 about the proposed amendment and whether it should be allowed on next year's ballot.