My question is for a specific example; however the strategy replies could apply to any departure and destination airports.

Any suggestions on how to obtain lowest RT airfare from SAT (San Antonio) to KOA (Kona big island) in Oct 20-27, 2012? 7 nights at Kona Resort confirmed 1 year ago.

The airline schedules recently became available for Oct 2012. I checked Expedia, RT air SAT to KOA >$1200. Ouch. In 2011, fares in the summer for Oct were running around $750. I am seeking Strategy suggestions on how to get the best airfare.
I am Platinum on American Airlines (AA). I would prefer to stick with AA and their partners to earn more miles for future trips and continued elite status.

On Expedia, American RT to SEA for ~$268 on those dates. RT via Alaka Air SEA to KOA is $604. $604 + 268 = $952. Cheaper than the > $1200 route.

Any other suggestions? Does any recommend Orbitz Price Assurance (limited to $250 back if another person books thru Orbitz cheaper)?