In a hypothetical graduate job market, a high type earns 120 if recognised and 80 otherwise. A certificate has no productivity effect. It costs a high type 6 per unit and a low type 15 per unit. Low types produce output worth 80. If certificate level 4 identifies a worker as high type, find the high type's net gain from choosing level 4 instead of zero.

Please enter a number only. If your answer is a decimal, round it to no more than two decimal places. Do not include spaces, commas, letters, or special characters such as dollar signs.