Once a man asked Gautama Buddha what my value was. In reply Gautam Buddha gave him a shiny stone and told him to go to the market and find out the price but would not sell it to anyone.
According to Gautam Buddha, the man went to a market. At first he took the stone to a mango seller. The man showed the stone to the mango seller and asked him how much he would pay for it. Then the mango seller said I can give you ten mangoes instead.
This time the man went to a potato seller and asked the same question. The potato seller said I can give you a sack of potatoes instead.
Then the man went to a gold shop nearby. The goldsmith looked at the stone and said I can give you ten lakh rupees instead. On hearing this, the man was leaving the shop when the shopkeeper said, "Well, twenty lakh rupees," but when the man was leaving, the goldsmith said, "Well, tell me how much it will cost, but go through the stone."
The man left without saying a word and went to a diamond trader. The diamond trader looked at the stone carefully and said that it is so old and very precious, it is a rare stone and it costs at least 50 lakh rupees.
This time the man returned to Gautama Buddha and told him everything. This time Gautama Buddha said that you are like that stone, that is, your value is also different for different people like this stone, but it depends on who you are checking your value with.