Isekai Furima: Kotsutouya no Musuko ga Sute Sozai de Ikkaku Senkin Neraimasu!

From rags to quick riches?! Yusaku Kobayashi grew up in a family running an antique store. He started making a lot of money selling some of the antiques online as well! While cleaning the storage room, Koboyashi gets sucked into a cursed mirror he found sitting in the corner. He was sent to another world! Stuck in a new world with nothing but the clothes on his back, he's attacked by a giant golem! However, just in the nick of time, he's rescued by a treasure hunter by the name of Melca. Kobayashi learns from her that this world that's now overrun with monsters has a magical system that sells items in a way similar to online markets! Now he is determined to sell loot from monsters through this online market, and use the money to buy an expensive magic item that could bring him back! Will Kobayashi be able to get back home?! Now starts a fantasy adventure, with riches to be had! (Source: MangaPlaza)