Within 72 hours of the flight if you haven't been upgraded you can usually change your seat to Premium for free. The First class upgrade is hard to get on space alone with an "O" ticket as an MVP gold because it's almost the last ticket class in line to get upgraded to first but it has happened to me many times in the past. The actual true saver fare is a "X" ticket class and that will only let you upgrade to Premium for a fee and doesn't allow any upgrades due to status. Im flying on an "O" ticket this weekend and am about to hit my 72 hour window. Premium upgrade is currently $72. After 9pm tonight I'll check and see what the cost is once I'm within the 72 hour window.