You can offer whatever you want, anytime you want, but chances of being successful with that low of an offer would be very low. The seller may owe too much to drop the price a dime without it becoming a short sale. They may be ignoring the advice of their agent who has suggested price drops or going off the market.
Find a local agent to assist you and discuss your interest in the home and your strategy. They can research the home and either advise you or write the offer that you both agree makes sense.