The price which an item would fetch in an open market. Distinction should be made between value in present use and value in alternative use. For instance, a factory building may be worth £500 to a person wishing to use it as a factory but £50,000 to a person wishing to redevelop the land. Value is also determined by various other factors, ranging from sentiment to long-term speculation; so, it is in fact a rather imprecise term.
Reference: The Penguin Business Dictionary, 3rd edt.