This is not dissimilar to Ko Bu Bu, which I described above, only the size of Ko Hai is larger. Again, you have the standard combination of a large piece of sand, surrounded by calm turquoise blue waters, thick vegetation in the middle, and a few bungalows complete with bar and restaurant, altogether with friendly locals willing to make your stay more enjoyable.
At the time we visited the beach (shown on the photographs below), there was a large "For Sale" sign with a quoted figure of USD$15,000. A quick inquiry in the bar suggested that the price included the beach, the restaurant and bar, and 15 bungalows.
Thai law does not allow straightforward ownership of real estate by foreigners, so things must have been a bit more complex. In addition, my visit to Ko Hai was pre-tsunami, so God knows what happened to these flimsy structures. But the natural beauty of the place must have eventually prevailed, and I am pretty certain that its touristic/commercial future is secure.