This Diwali, bursting crackers is set to become expensive with prices rising by around 15% amid higher raw material costs and supply disruptions in Sivakasi, the country’s fireworks manufacturing hub. Madurai: Firecracker buyers face a 15% to 20% increase in retail prices this Diwali as soaring raw material costs and production curbs squeeze Sivakasi, the country’s fireworks hub.N Elangovan.