Jim and Jane, both aged 33, are married with their 5-year-old son, Johnny. The family is currently living in a 3-room HDB flat in Yishun. They bought it when they first got married 6 years ago and have taken a HDB loan of $300,000 over a 25-year loan tenure. All along, the couple has been servicing the HDB loan using cash. This is because Jim does not contribute to his own CPF account as a SEP, while Jane has not been working until recently.

As the couple have plans to have another child, they are thinking about upgrading their HDB flat to a 2-bedroom Private Condominium near Farrer Park MRT Station. The Condominium is estimated to cost $1m. It looks like a significant investment, but the couple felt that they can tighten their belts in order to provide the family with a better living environment, and fulfil their aspiration of being a real-estate owner. Currently, the most competitive mortgage package is from ABC Bank at an interest rate of 1.5%.

Determine the mortgage outstanding on their HDB Flat.