I have not seen anywhere a law in Pakistan that a car cannot be sold under a certain price.
All of you are talking in open market, making your own guess about car value. There is no Kelleybook value in Pakistan. there is no official website which states a stock car's price or depreciated price by law.
To talk so boldly about anyone selling lower than a given price you should have a written back up about actual depreciated price of a stock car.
and there is none!
only word of mouth. and a lot of word of mouth in open market.
i can do this, i can do that, i can get this cheaper, that is not right, this must be wrong.
all this without any written official backup found in Pk and no protection from salvage cars. 
In general there is too much discussion and very less outcome.