why does itunes only show "free" books?
Why does itunes only reflect the "free" book choices and never ones I can purchase?
iPad 2, iOS 5.1.1
Almost certainly because Apple has been unable to obtain the necessary licenses from the content owners in your country to allow them to sell books there. You can see a complete list of the types of content available in your country here:
http://support.apple.com/kb/TS3599
Regards.