Agree 100% with that.Linjeakel said:
If you don't like the price, then don't buy the book and write the publisher stating why you didn't buy the book. Maybe write the author too so they'll have incentive to put pressure on their publisher and/or choose a new publisher when their contract is up.
Don't give a false review and possibly turn others who may be ok with the price off from buying the book. That's dishonest and not fair to the author.