As far as books and magazines go, it is always cheaper
to ship using the
US Postal Service book rate. You must request it at the counter. In some
cases you can save up to half the shipping costs.
What they don't tell you is that this is the same thing as third class
postage, and when you send stuff third class, it moves from post office
to post office *only* when the trucks aren't full of first and second
class mail.
I had a guy mail me three boxes of Prime manuals from South Carolina
using the book rate; two boxes arrived in about 4 days; the third box
took another week and a half before it arrived.
Caveat emptor....
-dq