Veggie stir-fry was estimated to serve a banquet of 40 guests. The standardized recipe established the food cost to be $2 for each 8 ounces portion. However, an inexperienced cook made each portion 10 ounces, which increased the cost to $3 per portion and decreased the portions count to 30. Each portions selling price is $6.

What will be the profit loss because of this mistake? Show the calculation, not just the final answer.