Shopping in Both Worlds, Mineral Water at the Beginning Is Exchanged for Gold!

Double wear [ancient + urban], don't abuse the owner, and have a great time taking off all the way! After graduating from college, Shen Yiming was surprised to find that he could travel to an ancient world in his security uniform! And this ancient world seems to be experiencing famine! Food and water are extremely precious! A modern bottle of mineral water can be exchanged for gold! Two bottles of modern eight-treasure porridge can be exchanged for an oiran! Shen Yiming exchanged materials with each other in the two worlds and continued to accumulate wealth and power! In modern times, it's not too much to become the world's richest man in one year, right? In ancient times, it took two years to unify the world. Is this reasonable?