The May 2026 duty hike

Suppose on 12 and 13 May 2026 gold is $4,500/oz (an illustrative round number; the Yahoo Finance GC=F front-month COMEX futures closed at about $4,687 and $4,707 on those days) and USDINR is 95.4 on both days (the Yahoo Finance INR=X close was 95.39 on 12 May 2026 and 95.63 on 13 May; we hold it fixed so that only the duty changes). Compute the import-parity price per 10 g before and after the hike from 6% to 15%, and the percentage change. Then compute the retail price including 3% GST after the hike.