Originally Posted by
mvoight
As the OP didn't say anything about awards, I assumed he meant paid tickets.
I don't see any yadvantage in getting one way tickets for a round trip journey.... I don't assume he has enough points for the award tickets, or if there is availability (assuming milesavers)
Originally Posted by
swag
In cases like this, the benefit of separate one way tickets is that you can change or cancel one direction without affecting the other.
To summarize...
On two paid one-ways: if you change the outbound or the return, then that direction gets repriced to current fares as of the date of change. You also pay the change fee, if any.
On one paid round-trip: if you change the return only, that can be done for fee only, possibly, inventory permitting (but advance purchase waived). Changing the outbound reprices both directions to current fares as of the date of change.
Even a Y fare doesn't guarantee "free" outbound changes; in practice, however, Y fares don't fluctuate a lot so there is usually no fare difference to collect.