This is imperative for saving money in Korea. You’ll likely have to shop at a big mart (Home Plus, e-Mart, or Lotte Mart) for some of your groceries and other necessities (ie. Korea has a big focus on locally grown produce, and typically you’ll only find what’s in season at the smaller marts. Sure, you can sell some of your bigger items when you leave Korea, but you likely won't get much money back. Don't purchase big items on the assumption that you'll get lots of money for them at the end of your contract.