Do books cost more when pre ordered?

Usually, from personal experiences I have noticed some things.

1. When ordering from Amazon.com/.ca there is usually a deal. Maybe a couple of dollars then it would be in stores when it just came out.

2. If the book is unpopular or people have stopped buying it, the book price will drop. For example: the steve job's book dropped over 50% from like, 42.00 to 20.00 because people stopped buying it.

3. If you dont mind waiting, go to a used bookstore and you might find it for a low price in great condition.

4. Also, preording off ebay.com/.ca can be cheaper.

HOPE THIS HELPED