Plus the box plus the tape plus the padding plus the labor to wrap it up,
put it in the box, tape it up, and write out the label.

On two occasions I've paid what I thought were outrageous
shipping charges, because the total cost wasn't too far out of
line. In both cases, the items arrived *very* well packed, using
those expanding-foam bags (which aren't cheap).

This is a bit of a gamble, though, because some sellers know how
to pack stuff and some don't. On the whole I've done OK by
avoiding sellers who are obviously clueless.