TORONTO -- The fast-food burger keeps getting more upmarket and expensive, and an analyst says that trend isn't going away.

Last year, Canadians bought nearly 15 million burgers at an average price of $6.05, says Robert Carter of NPD Group, which represented a four per cent price increase compared to 2013.

He notes growth in the burger business over the last five years has been dramatic, with "a lot of focus on the premium, high-end burgers with a lot of dialogue around the local and hormone-free and what I'll call the 'better-for-you-style' burger."

"Almost every restaurant now talks about hormone-free, or Canadian farmers, or antibiotic-free, or organic," Carter says.

"It's catering to the consumer demand to understand more about the foods that they're eating, and that also leads into the perception of health and wellness."

Bareburger, an American chain of organic burger restaurants, opened its 23rd location -- and first outside the U.S. -- in Toronto in January.

Euripides Pelekanos started grilling organic burgers at his nightclub in Brooklyn, N.Y., before opening the first Bareburger in 2009.

The menu caters not only to lovers of meat, but also vegans and vegetarians, and those on gluten-free, paleo and low-carb diets.

The full-service licensed restaurant offers burgers made of beef, bison, wild boar, elk, duck and turkey, with toppings ranging from pineapple relish and tomato fig jam to wild mushrooms and smoke sauce. Vegetarian patties include quinoa, black bean, or sweet potato with wild rice, and can be wrapped in collard greens or served on a brioche, sprout or hemp milk bun.

"There's something to be said about knowing where your food comes from, knowing that animals were raised right, the right way nature intended them to be raised, from pastures to being grass-fed to being free-range," Pelekanos said during a visit to Toronto.

Bareburger plans to open 18 more stores worldwide by the end of 2015, including several more Canadian locations.

Other U.S. burger businesses have similarly sensed an opportunity in Canada, including Five Guys Burgers and Fries, Wahlburgers and Carl's Jr.

But that's not to say homegrown upscale burger shops aren't doing well.

Shant Mardirosian, who launched a tiny Burger's Priest location in 2010, now has six in Toronto, one in Guelph, Ont., and one in Edmonton.

Mardirosian, who attended seminary school and uses aspects of his Christian faith as a marketing tool, says simplicity and freshness are the hallmarks of his classic American-style cheeseburgers, with premium beef patties on a soft white bun.

"We grind our beef on site and that beef is never used the next day," he says.

"If we run out of meat, we close the doors and sell out. If we have beef left over, we fry it up and make chili out of it for our chili cheese fries."

Business is booming and Mardirosian is opening five more shops, including one at Toronto's Union Station and others in Ottawa and Calgary.

Carter says many Canadians will shell out extra for a burger they believe to be of high quality. In fact, if it costs too little, more discerning consumers may think it's inferior and won't purchase it.

At Bareburger, a basic burger, fries and a bottled water will set you back around $17 after tax. Indulge in all the fancy stuff -- say a bison burger with cheese, brisket and guacamole -- and a combo rings in at about $28 after tax.

"These are extremely delicate, high-quality (burgers). There's been a lot of work sourcing these ingredients and there's unfortunately a price that comes along with that," says Pelekanos.

When The Burger's Priest opened five years ago, Mardirosian's cheeseburger was $4.99. Now it's $5.79.

"You can get away with a cheeseburger combo for about $12. Considering we use four ounces of premium beef, compared to some of the fast-food joints where they're charging $9, for an extra $3 I think it's quite a bargain."