My brother just charged his friend $700 for offering a bet: if the temperature of tomorrow is above 78, my brother will pay 1.5 times $700 to his friend; if the temperature is below 78 tomorrow, my brother will pay 0.5 times $700 to his friend. I do not want my brother to lose money when tomorrow's temperature is above 78 and decide to buy an insurance that will make my brother break even when tomorrow's temperature is above 78 (in other words, the insurance policy will pay my brother 0.5 times $700 when tomorrow's temperature is above 78). If risk free rate is zero, how much should I pay for this insurance (keep two decimal places)?