It doesn't hurt to ask

Two days ago, I picked up a very nice art book called Master's of Deception: Escher, Dali & the Artists of Optical Illusion . It features the work of many extremely talented illusory artists and at $19.95 Canadian it was an extremely reasonably priced book considering it is full colour and quite large. The problem was that the bottom edge of the book was dirtied and slightly damaged. I looked for another copy but could not find one. I asked at the cash if they had any undamaged copies and they found another, but it too suffered from the same imperfection. I asked if another store had any copies. They did, but it was in worse shape then the ones I had in my hand - the cover was torn. So I took the least damaged copy, they gave me a 20% damage discount (book is now non-returnable) and I got an additional 10% off because I'm an iRewards member. (Going online, I see I could have got an immaculate copy for pretty much the same price). Being religious, I find this picture by Octa...