Agree with all of the above re the tanking AUD - I was in Waikiki 2 weeks ago and, whilst the state tax is relatively low, the base prices for goods are higher than in Vegas (heavily subsidised) and LA.
The shopping is comparatively ordinary (Waikele Premium Outlets) compared to those in LA, Vegas and New York, although the Ala Moana Center is pretty impressive.
It's changed a lot in 20 or so years - it's very touristy, and I'd describe it as an overblown Surfers Paradise - I'll be one less returning traveller, not assisting those loads - YMMV.
The best shopping on Oahu is NOT Ala Moana - that is a tourist trap of grand proportions. It is the place 'to be seen' and the tour guides get a commission for taking coaches there (like with the Chinese and Jap tourists in Sydney). Worth a walk around and has some great food places.
On one of the early trips there (got addicted) was talking to a local at the international markets and she told us of several other malls etc to go to. One (I forget the name) has a monorail for getting around within it.
Depends what you are looking to buy as to whether you get 'value'.
Years ago the amount I saved on a bike frame more than paid for the 7 night package cost. Some other items are much more expensive - really depends for electronics whether made in China or not.
Totally agree that Waikiki is tourist central - go one block back from the beach and its a concrete canyon that could be anywhere (apart from the near-perfect weather most of the year).
Last time there one thing was still dirt cheap, no make that two: coughtails & ABC Stores Aloe Vera Gel.
The Gel (anyone going!!!) looks like green slime, and oozes as you'd expect. Used to be in a clear plastic approx 400ml bottle with yellow writing on it. Cost less than USD5. If still available it is worth 10 to 20 times the price.
If you turn out like a lobster (by mistake) and rub this stuff on the same day then most of the time you don't peel and the pain is gone by the next morning. It is incredible stuff but I can't see it in their online shop (not fancy enough I suppose).
Been a few years since last trip there and the 4 bottles we brought back finally ran out late 2014. Some neighbours begged us for it after our kids were OK next day and their's were still suffering from the sun burn.