Transportation fees are simply the cost of doing business, it doesn't matter which way the goods are headed. A bale of cotton woven into fabric in Massachuesetts will have transportation costs added in at each step in the process just as a keg of nails made in Pennsylvania or Liverpool and sold in Georgia would. Do you know the transportation cost for a keg of nails from Pennsylvania to Charleston vs. from Liverpool to Charleston? I don't, but it would be interesting to know just how much of a difference there is between domestic vs. foreign suppliers.
As for taxes, what taxes are you referring to?