Continental Airlines is joining the growing number of airlines that are giving members the option to buy additional miles in conjunction with a flight. OnePass members will be given the option to buy double or triple miles when checking in for a flight. Similar to the prices charged by American and United, OnePass miles are expensive and overpriced at around $.03 per mile. For example, it would cost $83 to purchase double miles (an extra 2,565 miles) on a flight from San Francisco to Newark and $165 to purchase triple miles (an extra 5,130 miles). Unlike its predecessors, Continental is also introducing the option to purchase elite qualifying miles, which in this example, would be $129 for double EQMs and $257 for triple EQMs–around $.05 per EQM. But in order to buy the EQMs, you have to buy the redeemable miles first, so you’re effectively paying around $.08 per EQM, which means that it’s cheaper to do a mileage run than to buy EQMs at the airport. But if you are short on time and only need a few more miles to qualify for elite status, this option may be useful. Do the math first to calculate whether the miles are worth the whopping $.08 per EQM.