It is at least possible that a manufacturing ecosystem would be so difficult to develop that it would require fewer decades to transport products than to develop that ecosystem.
Such comparative advantage would likely disappear overtime, unless a given solar system actively keeps its technological know-how secret in some way, or controls the travel of skilled people (as in nuclear tech today). Or, perhaps, some solar systems may fail to create the institutional context necessary for building such a system — if, for example, they keep nuking themselves. In any case, it's not too hard to imagine scenarios in which such trade would be necessary.
Such comparative advantage would likely disappear overtime, unless a given solar system actively keeps its technological know-how secret in some way, or controls the travel of skilled people (as in nuclear tech today). Or, perhaps, some solar systems may fail to create the institutional context necessary for building such a system — if, for example, they keep nuking themselves. In any case, it's not too hard to imagine scenarios in which such trade would be necessary.