The best information I can find on the issue is
this pdf from American Libraries Magazine. It was last updated last April. While this is a US based document, my guess would be that terms to Canadian libraries are quite similar.
So the Random House division of Penguin Random House charges roughly 3-4 times the HARDCOVER price of a book to libraries. On the plus side, the licenses are perpetual.
The Penguin division on the other hand, charges about the same as what they charge consumers, but the license is only for a year.
HarperCollins also charges roughly what they charge consumers, but the license is for 26 loans. This
is the subject of an informative YouTube video.
MacMillan both charges more ($40 for a backlist/$60 for a "within the last six months" title) and has a term limit: 2 years or 52 loans, whichever comes first. (See the video above.)
Simon & Schuster generally charge a bit less then the hardcover price for a 1 year lending period. They recently (Nov 2014) dropped their "Buy it now!" website button requirement.
Hachette currently charges three times hardcover for a perpetual license. Pricing is "at their discretion" though and subject to change.
So basically, libraries are getting gouged. The best ones are Random House & Hachette and even there they're getting charged through the nose for an individual copy.