The issue of e-book prices has sparked a global controversy as publishers lock horns with book retailers over how much consumers should pay.

Amazon has challenged some publishers on the question of the price of a book – the online giant would prefer to set a price point of $9.99.

Some consumers, online retailers and even authors complain existing e-book prices are too high, compared to the cost of print books.

As CBC’s Margo Kelly discovers, publishers are arguing they can't lower the cost of digital books too much or they won't survive.

"The strategy is to maintain value in what we produce, so whether that's the print book or the e-book, this costs 'x' to make and we need to maintain that to stay alive," says Sarah MacLachlan, publisher of Toronto's House of Anansi Press.

MacLachlan adds that printing and distributing books is only a fraction of the cost of producing a book.

Canada's e-book retailer, Kobo, is allowing publishers to set the price of some of their e-books and that’s meant a wide variation in what consumers are expected to pay.

Kobo executive vice-president Michael Tamblyn says the e-book company cannot push publishers too hard on pricing.

He predicts publishers will continue to experiment with prices, trying to strike a balance between a pricetag low enough to attract more sales and high enough to keep themselves afloat.

Meanwhile officials in Europe and the U.S. are investigating allegations that five international publishers, including Pearson PLC and News Corp., conspired with Apple to fix the price of e-books.

"The commission will in particular investigate whether these publishing groups and Apple have engaged in illegal agreements or practices that would have the object or the effect of restricting competition in the European Union or in the European Economic Area," the European Union's executive commission said in a statement.

U.S. regulators have also expressed interest in examining how e-book prices are set.