Well I do not know if it's going to be profitable but at least the foundation of interstellar trades have already been studied: there's a published paper on it

Well I do not know if it's going to be profitable but at least the foundation of interstellar trades have already been studied: there's a published paper on it by Krugman (https://www.princeton.edu/~pkrugman/interstellar.pdf https://www.princeton.edu/~pkrugman/interstellar.pdf)