It is well worth spending the money on a good-quality extra-virgin olive oil, since it can bring life to a myriad of dishes. Once opened, though, oxidation begins to breakdown the olive oil, shortening its shelf life dramatically. Storing oil in the fridge can help prolong its freshness, but the chill of the fridge will cause it to solidify. So keep a small bottle out on the counter and the rest in the fridge. That way, you will always have fresh olive oil when you need it!