Apocalypse Tycoon: I Sell, I Rule

The store Ethan runs in the wasteland lets nothing from outside through its door and never runs out of stock, and he sells bottled water and cola from it, by the unit, to people who have been beating each other bloody over a single bottle. Ethan woke up in this world, where acid rain has been falling for three years and the animals outside have changed shape, and found he had been given a supermarket. When an S-class creature breaks in, he throws it a can of coffee and tells it to drink first. It drinks, passes out, and wakes up on staff. He hires four women with powers of their own, all of them S-class fighters, for the price of some instant noodles, and they end up stocking shelves, keeping the books and minding the warehouse. When a horde of the dead comes toward the store, he has the staff ask them whether they want a job at one bottle of mineral water an hour. An SS-class creature applies for head of security because his store is the only building left with air conditioning. He wins an entire tribe over with one packet of snail noodles. He gets control of the water supply, and through it the economy of the wasteland, sells the crystal cores taken out of the walking dead, and issues his own coin. When the federal governor invites him to dinner, he sends back word that dinner is fine once the governor has signed a distribution contract. His own shipping fleet mutinies and the governor sets a trap for him, and he uses both to grow the business. He opens branches through portals, some of them far outside the wasteland. Within a year the chain has stores across the wasteland under his name.