Case 1: Unit price = $10
Profit = $3 * 1m = $3m
Case 2: Unit price = $9.50
Since cost per unit is constant which is $7, therefore profit per unit is now $2.50.
Profit = $2.50 * 1m * 1.10 = $2.75m
Therefore the increase in sales volume does not offset the decrease in profit margin.