Why spices demanded more infrastructure than silver

Portugal's strength lay in moving goods and exploiting a geographical position that Spain had tried to constrain. The papal division of overseas expansion reduced conflict between the Catholic powers but directed Spain toward American silver and Portugal toward eastern trade. Silver arrived as money that could be spent with little further infrastructure, whereas spices had to be shipped, stored, protected, maintained, and sold. Those requirements forced Portugal to invest in transport and supporting facilities instead of merely consuming revenue. In this interpretation, that accumulated infrastructure helps explain Britain's later preference for basing Peninsular War forces in Portugal rather than Spain.