A few other points -

1) No change penalty on any fare, even the lowest nonrefundable.

2) No hassles about back-to-back tickets. They even encourage it.

3) You can transfer unused funds to any other person with no fee or penalty.

4) If you need a 1-way ticket and a RT is cheaper, the same as the 1 way, or even just a little more, you can fly the one way and then reuse the value of the return segment toward any other ticket for yourself or anyone else.