Reasonable for Hawaii tends to be about 600 RT. It varies a lot of course, but from West Coast to HNL expect $300 RT to be as low as you can find in low season, more like $4-500 in shoulder season, then add on however much you would usually pay to get from your home city to the West Coast. We often buy seperate airfares going to the West Coast then switch to SW since it many times works out cheaper that way. You have to exit the terminal and recheck your luggage but well worth saving a hundred or two IMHO. Good luck!