Colorado regulators want to know: How much does marijuana cost?

Colorado regulators have begun surveying marijuana businesses about the price of pot in an effort to implement a new excise tax that voters passed earlier this month.

The tax places a 15 percent levy on the wholesale price of recreational marijuana when it moves between the grower and the seller.

The challenge, though, is that Colorado’s forthcoming recreational marijuana industry won’t have a true wholesale market for at least the first nine months. Instead, marijuana businesses must initially grow almost everything they sell — meaning the wholesale transactions that will be subject to the excise tax are really just pot transfers between two parts of the same business in which no money is exchanged. Businesses are allowed only a small number of transactions in which they can buy marijuana grown by another business.

To still collect tax on in-house transfers, Colorado regulators will determine an “average market rate” that will apply to all grower-to-seller transfers.

“It’s really difficult to figure out what that’s going to be,” said Meg Collins, the director of the Cannabis Business Alliance, a marijuana trade group.

That’s where the survey comes in.

The questionnaire asks businesses how much marijuana they grew in the past year and how much they sold to other businesses — and at what price.

Mike Elliott, the executive director of the Medical Marijuana Industry Group, said he’s worried such an approach will lead to an inflated average market rate. The transactions between businesses — what state regulators calls “arm’s-length transactions” — are the most expensive transfers, Elliott said. Applying the price of those to in-house transfers could lead to businesses paying more tax than is fair, Elliott he said.

“There isn’t a huge market for these arm’s-length transactions because people are barely meeting their own demand,” Elliott said.

Colorado regulators are also looking to differentiate between wholesale transfers of different cuts of marijuana. Buds, the most highly prized part of the plant, could be given a higher average market rate. Trim and leaves — leftovers from processing that can be used to make marijuana-infused products — could see a lower rate.

Daria Serna, a spokeswoman for the Department of Revenue, wrote in an e-mail that a public hearing is tentatively scheduled on the tax issues for Dec. 17. The tax rules are expected to be in place by Jan. 1, when the first retail marijuana stores open.

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/john_ingold