The arrival of new airlines and routes to Hawaii continues to pay dividends for travelers. Where flight prices might have been $600 round-trip in previous years, you can occasionally find tickets for less than half of that now. That includes getting to the island for less than $300 all-in right now.
You can find flights from a handful of airlines for awfully cheap, including some round-trip fares for as little as $297. Airlines with low-cost flights right now include Alaska, Hawaiian, American, Delta, and United, as noted by Scott's Cheap Flights. The majority of the best-rate flights are available between either April and June or August through October.
Some of the best deals on flights to Honolulu, Kona, Kauai, and Maui available right now include Las Vegas (to Kauai for $367), Los Angeles (Kauai for $348), Portland (Kona for $327), San Diego (Kauai for $378), San Francisco (Maui for $297), San Jose (Kauai for $298), and Seattle (Maui for $353).
Of course, as you'd find with any flight deal, the prices can change rapidly. If you're looking to take advantage of these, you should buy soon because options can disappear and prices can rise when fares are this low.