A made-in-New Brunswick beer battle with far reaching consequences was back in the country's top court for a second and final day Thursday.

The Supreme Court of Canada will ultimately decide if a Maritimer's argument for purchasing cheap alcohol in Quebec should be the foundation for re-evaluating cost-to-coast trade.

Gerard Comeau was charged in 2012 for buying beer in Quebec and taking it home to Tracadie-Sheila, N.B. A provincial court ruling last year found that any limit on provincial-border alcohol imports was unconstitutional.

Fredericton restaurant owner Doug Williams is watching.

“There should be no interprovincial trade barriers in Canada,” he says. “You should be able to get in your car and buy whatever you want anywhere in Canada that is legal and take it home.”

New Brunswick Crown prosecutor Bill Richards argues that current trade barriers are needed to keep the government financially afloat.

“I am not shying away from the fact it's a money maker. It is, but it’s necessary,” says Richards. “The hospital, the doctors, the medical systems paid by the province, all these things are paid by the province. The province has a very legitimate interest in raising money through the sale of alcohol and therefore the control of alcohol.”

Changing the law could change interprovincial trade on a wide variety of items, including dairy and wheat.

“We will really be introducing a great deal of uncertainty, perhaps increased litigation into the law,” says Supreme Court of Canada Chief Justice Beverley McLachlin.

“There might be initial litigation but the provincial officials who put these barriers in place are capable of reading your judgment, seeing the handwriting on the wall and negotiation,” says Comeau’s lawyer Ian Blue.

After two days in court, the Supreme Court judges are expected to report back with a decision sometime in 2018.

With files from CTV Atlantic’s Nick Moore.