As far as we know, tears consists of water and 0,9 gram salt per litre. And both of these ingredients are not free.
Here I listed the price of 10 litre tears for the countries of the G8.
I used the following formula (price is in US Dollar):
(price 100 gram salt/100)x9 + (price 1 cubic litre water/100) = price 10 litre tears
France: 0,20 $
Italy: 0,17 $
Germany: 0,19 $
United Kingdom: 0,22 $
USA: 0,18 $
Canada: 0,18 $
Japan: 0,18 $
Russia: 0,16 $
That means russia has the cheapest cry.