Liaison office of Grand Ayatullah Sayyid Ali Al Sistani (L.M.H.L) in London, Europe, North and South America.
The following are Mustahab in connection with sale and purchase:
One should not discriminate between various buyers while charging for the
commodities, except in the case of poor people.
One should not be adamant about the prices, unless one feels that one is
being duped or cheated.
One should give a little more of the thing one sells, and should take a
little less of the thing which one buys.
If the buyer regrets having purchased something, and wishes to return it,
the seller should accept it back.