If you're looking for a bargain on a ring, postpone your proposal. By Anne Kates Smith, Executive Editor January 7, 2009 Planning to pop the question on Valentine's Day? Go ahead. But you might want to pause before you buy the ring, and be ready to haggle when you shop for it.Platinum, a favorite setting for diamond engagement rings, has been plummeting in price since last summer. The metal, which is also used in catalytic converters in car and truck engines, peaked at $2,276 an ounce last March, hovered at about $2,000 an ounce through July, then plunged to as low as $788 an ounce recently. You'd have to go back to the summer of 2004 to find it cheaper. Though far rarer than gold, platinum is trading at less than a 10% premium, thanks to reduced industrial demand for platinum and greater demand for gold as a safe haven. Sponsored Content But jewelers don't turn over inventory very fast. "They have to get rid of the high-cost platinum jewelry first," says Ken Gassman, of the Jewelry Industry Research Institute. And diamonds, which account for 80% or more of the cost of a ring, have not fallen in price. Still, look for bargains by the end of the first quarter, says Gassman. On a $6,000 engagement ring, you might see savings of $500 to $600, he predicts. "That will go a long way toward the cost of a wedding band."