I agree with the previous post. I think you should pursue the one-way option. I'm doing it this summer, but in Y class. Cheap student one-way to London, round-trip back and then another one-way. I get the two trips (even though on three tix - two o/w and one r/t) for a third off what I would have paid for two r/ts in the USA. I've been assured by posters on this board and the airline concerned that this is legit (all of my flights are on the same airline to maximise elite miles.)