Elica — performance quality of hob

We had purchased hob one year back, initially the burner flames were not good enough leading to delay in cooking.
The service personnel visited twice he cleaned the burner nozzle and casting cabs. He said the casting cabs need to be changed for higher flame and quick cooking.
Yesterday again we called on serrvice engineer as flames were too low. Now this service engineer changed the burner nozzle and flame increased. But he said thecost of each nozzle was 3200. Replacing all burner nozzles will cost us almost 60 % of hob cost.
Is this strategy of your management for revenue generation