Refer to the original data. Management is considering using higher-quality components that would increase the variable expense by $5 per unit. The marketing manager believes that the higher-quality product would increase sales by 25% per month. Calculate the change in total contribution margin. Refer to the original data. Management is considering using higher-quality components that would increase the variable expense by $5 per unit. The marketing manager believes that the higher-quality product would increase sales by 25% per month. Calculate the change in total contribution margin