I buy major purchases from Amazon. Gang up your books into an order to more than $40, and they ship for free to your door.
US chain Borders pays 80% of cover price for books. A recent Globe and Mail article revealed that Chapters pays 48% of cover price. Result--two different prices for the same books so that both chains can pay the publishers the same money. Obviously, Borders can do well with a 20% markup.
A friend of mine self-publishes hard cover, historical quality books on railway topics, and will never deal with Chapters again.