I look up the words for them. 값 1.price 2.value 3.cost 4.charge 5.worth 가격 1.price 2.cost 3.value 4.charge 물가 1.price Actually, there's no/little difference between 값 and 가격. We use them alternatively. But 물가 is different. It's an economic term. When we say 값 or 가격 we think of a few products/items, but when we say 물가 we think of all kinds of products in the market. So it's the broadest concept of them. A country which devalues its currency faces increasing import prices. Price Fluctuations Require Intervention As an export-driven country, Korea has much to benefit from lower costs and stabilized prices.

값 = value; price 가격 = price 물가 = general cost of living 화장실 = WC 욕실 = bathroom

값 = value (the number itself, it could mean cost when you are talking about money.) 가격 = cost (only money) 물가 = price, but not just "price" but it contains the meaning of the price trend. Like New York's 물가 is more expensive than Seoul's. 화장실 = restroom 욕실 = bathroom