Pretty sure you could easily find some mileage runs from CMH that would get you the same amount of MQMs for far less than the expensive fare and the 120,000 miles you forked out to be able to upgrade with the miles. (I.e., just get the ticket to LHR with 125,000 miles round trip, and then use the cash you used to buy the ticket you bought to buy a couple mileage runs to get you the ~10,000 MQMs you'd me missing out on, which would certainly be cheaper than the fare you paid for, and would still be the same amount of miles basically - 125,000 r/t vs. 120,000 r/t). But to each their own.