In a few short days, it will become legal to sell marijuana in retail establishments. How much will marijuana products cost? And will you only be allowed to pay in cash? WGBH's Morning Edition anchor Joe Mathieu spoke with WGBH News Legal analyst and Northeastern law professor Daniel Medwed about these issues in the latest installment of our weekly month long series “Deep in the Weeds with Daniel”.

Joe Mathieu: So let's start with pricing. Are there any significant regulations governing the actual price of marijuana products in these establishments?

Daniel Medwed: It doesn't look like the state is going to regulate the base price. Good ole supply and demand should shape that. But two things seem pretty clear right now. First the prices can be fairly high at the outset due to a flurry of demand because of the novelty factor- people are in a rush to buy these goods. And second, there's a lack of supply because of the delay in issuing cultivation licenses. At the moment, medical marijuana locally is going for about $50 dollars for an eighth of an ounce. Second, that base price is going to be augmented by a steep tax- seventeen percent state sales and excise tax, coupled with the possibility of cities and towns issuing a local three percent tax if they decide to do so.

Mathieu: So somebody walks into a dispensary, Daniel, paying twenty percent. That's a lot higher than the general sales tax.

Medwed: You're right. The standard Sales and Use Tax in Massachusetts is just six point two five percent. But like many states, Massachusetts has implemented so-called vice taxes- a combination of sales use and excise taxes designed to discourage the use of certain products deemed to be problematic. Take cigarettes. They are subject to a combined sales and excise tax in Massachusetts of about forty percent. That means that a pack of cigarettes cost nine dollars here which I believe is the second highest price in the nation. Alcohol is just subject to the regular sales tax. But vendors of alcohol must pay a special excise tax that varies depending on the specific nature of the beverage. And all of us pay a fairly high excise tax on gasoline- 24 cents per gallon. So given those realities I don't think the marijuana tax is completely out of line with our approach to so-called vice taxes.

Mathieu: We're still going to have this local tax potentially imposed by municipalities which is not something we see very often right?

Medwed: You're absolutely correct. The option for cities and towns to implement a local tax of up to three percent is rather unusual though not unprecedented in our tax code. There is a local option for food and beverage though I think it's less than one percent. Nevertheless there's a solid rationale for doing it here. Marijuana represents this new frontier and the local tax option helps incentivize cities and towns to overcome their fears and sort of dip their toes into this nascent, daunting market.

Mathieu: Daniel the banking issue has been a big one that we have talked about. People will only be allowed to use cash to buy marijuana?

Medwed: In the early phase of the marijuana roll out, I think cash will indeed be the coin of the realm. That's because banks and credit unions are very leery of doing business with the marijuana sector, presumably out of fear that marijuana is still illegal at the federal level and banks of course are heavily regulated by the federal government. The FDIC insurance program and so on. That is a real concern but I think it might only be a short term one. Consider Colorado which legalized marijuana recreational use in 2014. Financial institutions were originally unwilling to do business with people engaged in marijuana activity but over time got comfortable with the idea and now a majority of operators have bank accounts. So there's reason to think that over time financial institutions will get involved in this industry.