Value and price are

#120500

Value and price are different, the concepts of bargain and rip-off occur when you pay above and below the value of a good.  You can buy something that has no value.  A work of art is unique, it cannot be reproduced, so it has no value (you can't buy another Mona Lisa), value only matters for reproducable goods.Value is not the same as exchange value: exchange value is when you express the relative value of a good by comparison to another.  By analogy, the length of any object is its length, it's relative length in centimetres is a relative expression of its length compared to light waves.  So when we say something is 10 centimetres long, we are saying it is one tenth of the distance that light trabvels in a certain measure of time.