Trade begins with wandering peddlars who trade what they can carry while walking. This is the prototype. Now, of course the intelligent among them make sure they carry small, high value items, LUXURIES.
You, on the other hand, probably would carry a bushel of wheat.
This concept of value equaling or exceeding transportation costs is probably too difficult for one still struggling to comprehend Treason but so be it.
Again, you are making no sense at all. Try concentrating.