How and when to use your miles vs. cash is really a subjective call. Inmy case, I use a pretty easy way. If fares are cheap, pay the cash. When fares are high, use the miles.

For example, fares from HNL-DCA have ranged from $500 to $1100 over the years. Needless to say, when the fares are over $700, I try and use miles rather than pay. Of course, there are times when there are no saver awards available (increasingly so) and then you have to decide whether to use the 60K standard award.

I think in the end, it comes down to timing, opportunity and availability.