I believe that the difference between mahalo.com and kupulau.com is significant. The word mahalo is well known worldwide as the Hawaiian word for thank you. The word kupulau, however, is unknown to most people outside of Hawaii. I think the the name is worth reg fee.
Mostly, I agree with what you guys said but forgot to mention one thing I've noticed while doing my search. I've tried quite a number of Hawaiian words I can find that is kinda pronouncable, 99% are regged.