OK...I probably have no idea what I'm talking about,,,but I'm going to say it anyways
When I was looking for property back in the old legacy city I would come across completely vacant, unowned parcels that were way more expensive than the empty lot next to it. I was told it was because there had been a property on that lot before. The lot kept the property value of the old house, even though it was no longer there.
Could that be the case here?
If someone had previously built on that island - which is VERY likely for all private islands - doesn't that effect the future buying price of that plot of land?
Now I've heard that the inflated price is also true of the cities grass/sand lots. All of them? If so, sounds like a bug to me, or something that will be resolved. Probably due to demand of housing.
If they just created the city anew in EA-Land, then that could mean that almost instantly, every house with a property on it was bought - an incredible real estate demand that would drive up the property value equation.
I don't know - just hypothesizing
mame