Originally Posted by Knobbgb

Are you talking about an A3 award or a *A award?

In the former case, I've never seen a situation where it can be cheaper booking two legs - they usually (always?) just add up the required miles for each flight.

In the latter, it's done by zones so unless you've found one of those tickets that pass through a more expensive zone before returning, it's likely to be the same price. Some idea of your actual itinerary would be helpful to answer the question.