Feather Friends, Inc., distributes a high-quality wooden birdhouse that sells for $80 per unit. Variable expenses are $40.00 per unit, and fixed expenses total $180,000 per year. Its operating results for last year were as follows:

Sales	$	2,160,000
Variable expenses		1,080,000
Contribution margin		1,080,000
Fixed expenses		180,000
Net operating income	$	900,000

6. The president does not want to change the selling price. Instead, he wants to increase the sales commission by $1.60 per unit. He thinks that this move, combined with some increase in advertising, would increase this year's sales by 25%. How much could the president increase this year's advertising expense and still earn the same $900,000 net operating income as last year?