Saint Sky Block

...it has up to 566 Prims (Land Impact, counted on a sandbox). Those two rooms or platforms are a little bit small, you can customize it for your own (e.g. add more levels). :) The Tower has a good design and a good quality (for me is this tower good).

If you are looking for a house or a tower like this for your parcel, then buy it. But you need a lots of rented prims.