Originally Posted by
ohmark
If so, then if, by some chance, the fare went down (as it did last year for me as to the bedroom), you could cancel, get a full refund, and book at the lower price?
Yes. However, it is very rare--probably even completely unheard of EXCEPT in the rare case that AlanB described above--that fares will go down. But if perchance the fare does drop (or if you find a discount code that lowers it), yes, you can cancel and rebook at the lower fare.
If you've already received your paper ticket, you can still exchange it and get 100% exchange credit, but you will receive a voucher good for the difference between the old fare and the new fare (instead of a refund).