Downtown HNL is very urban for a tropical island. Not really as relaxing as Maui.
Prices are always high everywhere in HI for lodging, meals,etc.
If you are a Costco member they do run hotel/car packages on several islands- both Oahu and Maui will have some decent deals.
The Royal Hawaiian is just drop dead gorgeous-yes it the Pepto Bismol pink palace on Waikikki Beach. It oozes old Hawaii charm.
It is also VERY expensive!
If you don't stay there then consider doing a brunch or dinner there to enjoy the glorious sunset views of Diamond Head. The Halekulani hotel is pricy but if you want a spectacular meal book dinner at La Mer.
Another option is to check out Air BNB? You may find a studio or 1 BR apartment close to the action but it may not be beach front.
Regardless, you will have a lovely time in Hawaii.