Korean has three distances: 이 for something near you, 그 for something near the listener or already mentioned, and 저 for something away from you both. They go before the noun. To ask a price, say 얼마예요?
Examples
- 이 셔츠 얼마예요?
- How much is this shirt?
- 저것을 주세요.
- Please give me that one over there.
- 모두 얼마예요?
- How much is it altogether?
The mistake to avoid
그 is not simply "that" - it points at what the listener has, or at what you have both just mentioned.
Where this fits in
음식과 주문, Korean A1: Order in a café, ask for things politely, talk about favorite foods, and ask for the bill.