I just got back from Hawaii... and stayed a couple of nites in Waikiki (crazy Halloween festivities I must say)
I stayed at the Castle Ocean resort which I got through priceline and at first I was a bit disappointed but the place kinda grew on me...it's a couple of blocks away from the beach and I had a really cruddy view but I only paid like $55 a nite via priceline with bonus cash....
Who stays in their hotel much in honolulu anyways and with the extra money you save you can afford to do more activities
Check out what current hotels people are getting and for how much on bidding for travel...
I also stayed at the Diamond resort in Wailea on maui for $95 via priceline and thought I would be dissapointed because it's not on the beach but the hotel was absolutely fantastic with excellent service and the grounds were beautiful and I had a car anyway so it didn't matter....
Anyway just try to get the best deal on a hotel you can...
As for the food it can be expensive if you let it....If I were you and really wanted to save cash find good deals on lunch specials and eat cheap food like subway for dinner.