Hong Kong had unilateral free trade throughout decades of almost uninterrupted economic growth. If you produce cheap products you develop expertise that you can leverage to eventually produce more expensive ones. This process of learning by doing does not depend on tariff barriers and tariff barriers will not make it work either. Argentina produced cars domestically for decades that were more expensive and higher price than the world market and as soon as tariff protection was withdrawn the industry disappeared, after having wasted millions of dollars over decades.