Everyone likes to feel he or she is getting a bargain, but discounting has made it easier for book prices to creep upward while maintaining the illusion that consumers are getting the books inexpensively. Since booksellers' markups aren't as big as those of other retailers, discounting can be a risky strategy that slices profit margins razor thin; recently, some have thought better of it. After growing accustomed to the sight of 20- and 30-percent-off stickers, suddenly consumers are being charged full price for many types of books, another source of sticker shock. Maintaining the illusion that books are affordable has gotten more difficult.