Buying a lived-in public rental home used to be a cheaper option for Hongkongers wanting to get onto the city’s famously steep property ladder.That may not be the case for much longer as soaring prices in the private sector spill over to government-subsidised homes.On Tuesday, the market was shocked when a 598 square foot, three-bedroom flat on the Fung Tak Estate in Wong Tai Sin, Kowloon, sold for HK$5.26 million (US$674,000), or HK$8,795 per square foot, making it the most expensive former…