I will need to fly from OGG-HNL-LIH with a stopover on HNL for 1-2 days.

I have the required 5K miles needed for an interIsland flight on AA.

And for my fiancee, I plan to give use 10K miles to get her an interisland flight using my CO miles.

BUT, for a total of 15K miles, Versus buying the tickets on Hawaiian, which is more cost effective? I am drawing a blank on how to figure this out.

Thanks!