if you want a book about pirce theory, you can download it from my post
http://www.pinggu.org/bbs/thread-704144-1-1.html , this is Stigler's book, The Theory of Pice; or
http://www.pinggu.org/bbs/thread-704155-1-1.html , this is Jack Hirshleifer's textbook, Price Theory and Applications 7th Edition
if you want a textbook cover a wider range of microeconomics, for introductory level, you may read Paul Samuelson's Microeconomics, for example...but i'm sorry I don't have Samuelson's e-book
i hope this can help you