Hawaii cruises come in 2 ways.
1. In and out of Los Angeles, San Diego, San Francisco or Vancouver B.C., 14 to 18 nights on HAL or Princess.
2. In and out of Honolulu 7 cruise or 10 nights (7 cruise and 3 land package) on NCL Pride of America.
On a quick look it looks to be less expensive to take the longer cruise in and out of the west coast then to take the Honolulu cruise. Also Princess and HAL are better lines then NCL. The only down side of the longer cruise would be if you do not like sea days (9 of them out of the 14 days and 1 day in Ensenada Mexico....so only 4 port days in Hawaii)
Now you made me feel old when I thought of how long ago I was in Hawaii (35 years ago when I was in University, back then we got round trip air and 6 nights hotel across the street from the beach for under $300.00 each)