Yep - Slippahs is right. In fact, I just did this for a trip this week. I'm going SEA-HNL and back this week and was able to buy a K fare and use 35,000 miles for the upgrade. Not a bad deal to be Plat

Even the phone agent was telling me how well it pays to be platinum. No WorldPerks admin fees at all, can upgrade all fares domestically (including Hawaii) and Plats don't pay the call center ticketing fee.

-RM