Yep, some decent rates can be had at some very nice hotels.
But here's a hint; if you want to rent a car in Honolulu so you can drive around the island, do it at the airport - it's MUCH cheaper than renting close to the hotels. Also, everybody charges for parking, so you have to plan to spend about $20 - $25 per day for that.
However, if you don't want to rent a car and only plan to go to Pearl Harbor, you can either take a city bus (cheap but takes a while), or get some coupons from your hotel as there are always shuttle services that don't charge a huge amount.
And lastly, but the most expensive option, there are a lot of tour companies who will provide all sorts of tours around the island.
Personally, I am so very glad we rented a car. We spent 2 days driving around the island, stopping at many places for pictures and sightseeing. It's a magnificent island with incredible beauty. Not to mention all the great food!
We met a local who recommended an out-of-the way place in Kaneohe that was incredible. The cook use to be a master chef at a 5-star resort and decided to open his own little restaurant. It was the best meal we had in our entire 3-week stay!
We also found a little shrimp shack on the side of the road on the north shore that had their own shrimp ponds in the back. Talk about fresh! The shrimp were still alive when we placed our order!! Can't get any fresher than that and the food was awesome.
You miss out on things like this when doing tours or shore excursions.
We took our GPS with us and it worked great getting us to all the places we wanted to see off the beaten path.