Respuesta :
They were expensive because they were rare in the west. They were rare, because the ways to bring them were a very long, dangerous and otherwise expensive trade routes, either through central Asia or through the Indian and Arabic peninsula coast, and later (after Vasco da Gama) around Africa.
reasons that eastern luxuries were expensive because it cost a lot of money to produce them and it was used to dignify status. Luxury goods are said to have high income elasticity of demand: as people become wealthier