My friend Web Kirby has proposed a sculpture park on Twinity for 3D art objects. This could be a case study for #mtw3 next week. He may be right that a 3D model would be secure in Twinity even if sold for a specific location.
There are a few issues with this. I don't understand how this sort of art is promoted. The Phoenix show starts next month so there may be discussion then.
If you are on Twinity, search for "Beach For You" in Northampton. I asked for a beach in East Devon but for some reason the map data came up with Northampton. For a beach. and this is the service they no longer afford for the big cities.