To estimate month-to-month typical costs, KAYAK will take all prices for on a monthly basis over the last year for business class flights to London, eliminates the top 0.one% to account for outliers, and afterwards normally takes the median of every one of the values for on a monthly basis. https://www.tumblr.com/businessclassflightdealstosydney/729912040095940608/tips-to-find-affordable-premium-economy-flight