i'm very particular about what books i buy and the price that goes along with them.
if its just a book of patterns, odds are i will not buy the book unless its around $10 and i have to like or want to make at least 2 of the quilts in the book.
if the book teaches a concept that applies to quilt making beyond the patterns in the book - i'm willing to pay more around $20.
when i do buy books it has always been thru amazon because they seem to have the best price.