To estimate the loan amount and downpayment for a 3-bedroom HDB resale flat in 2031:
- **Estimated Price in 2031**: $638,000 (based on a 5% annual growth rate from $500,000).
- **HDB Loan**:
- Downpayment: $127,600 (20%).
- Loan Amount: $510,400 (80%).
- **Bank Loan**:
- Downpayment: $159,500 (25%), with $31,900 in cash and $127,600 from other sources.
- Loan Amount: $478,500 (75%).