gccgrad -- the lowest of these fares are for midweek travel. Weekend travel goes up about $50 each, ($25 each way) based on availability. It looks like availability PVD-LAX is an issue on your outbound (is that President's Day weekend or something because availability is pretty tight)? Best case you'll get the PVD-LAX-PVD to price out around $223 with tax included, and the LAX-HNL-LAX to price out to $363 with tax included.

Go to Travelocity and enter your cities PVD-LAX and LAX-HNL being sure to select "My Dates are Flexible." That will show you the lowest fares. Select the Continental fare and it will bring up a calendar that shows when the fares are offered. Click on the dates and it will show you if there is availability on those dates.

These fares seem to go all the way into early June. Hope this helps.

If you can be somewhat flexible, the two of you will be able to get your Hawaiian vacation on a student and teacher budget!