BUENOS AIRES, Argentina, Jan 6 (Reuters) - It has rarely been cheaper to dance the tango in Argentina, which is why the number of foreign visitors jumped by a third in 2003, the government said on Tuesday. The steep fall of Argentina's peso, the product of a recent economic crash, has also filled the South American country's malls and boutique shops with bargain hunters eager to snap up local leather, wine and handcrafted jewelry. "Many tourists ... take advantage of the currency and the quality of service that has notably improved in Argentina," Tourism Secretary Enrique Meyer told local radio....