In an Unknown Realm, I Reign as Lord

Henry unexpectedly gained the ability to travel back and forth between Earth and a parallel world, carrying with him a pocket dimension. He became a middleman between the two worlds. On Earth, he traded a $50 glass cup for a territory worth $5 billion in the alternate realm. This ancient world resembled medieval Europe, with very limited industrial development, where Earthly goods could fetch prices thousands of times their original value. Through his trades, Henry became wealthier than the king. Countless princesses and elves sought to marry Henry and become his companions."