Originally Posted by Aus_Mal

While I can't back my answer to your question up with any real stats, I saw the following example today:

Bne-> Cns One Way Economy Reward.

Sun Aug 21
19:20 Brisbane 21:40 Cairns QF786 737-800

Cost = 20000 points

07:00 Brisbane 08:30 Sydney QF505 737-400
09:40 Sydney 12:40 Cairns QF924 332

Cost = 30000 points.

Same destination, same source city. Same class. Different points needed.