I read your original post. The median home prices I mentioned are for the entire state, including the Big Island. I'm not surprised your friend found a house for under $400k on the Big Island. I'll go out on a limb and say it's smaller than your 4/3, 3,000 sq. ft. home on a 9,000 sq. ft. lot. If you're looking for something like that here you'll be paying a lot more than $400k.
No doubt anything I like would cost more. I have no idea what his place is like. I am fairly particular, what suits him wouldn't necessarily suit me. Although we currently have a reasonably large home, we don't need this much space. There is just my wife and me and our two dogs at home. A extra bedroom for our kids and a bunk area for the grandchildren would be nice, but not absolutely necessary. We don't need a bunch of land either. A townhouse with decent sized patios would be fine. Although I really like gardening, there will come a time when it is too much work.
Not having been to the Big Island, I have no idea if I would like it. We have visited Oahu and there were neighborhoods in Honolulu that we liked. I doubt we could afford beach front property, but something walking or bicycling distance and perhaps with a view would be excellent. I like being in or near a large city as long as the neighborhood is good. Needless to say I am a good example of someone with champaign tastes and a beer budget. Well, there is always winning the lottery. LOL!