Price Limit

Several months-okay, maybe a year or so-ago Daughter told me "The Help" was a really good book.  I was too tight-wad to spring for the cost.  Now they have made a movie of it-aaaargh!  I know I cringe at paying more than a few dollars for a fiction book.  However, non-fiction books that I plan on keeping even though I have limited space, I will pay up to $35.00.  Why I came up with that limit I do not know.  Of course, trading books for free or second hand books for very little is one of my preferences.  Unless I count the free books I get on my Kindle.  Do you have limits?