Currently, the Shack tileset is listed among the more expensive and highly elaborate tilesets in T3. It honestly belongs in T2 as it uses lower quality materials (such as unrefined Fibre).
It fits better in T2 not just materially but also thematically - a swamp shack should not be equal in stature to Pagoda or Bhutan, and is more in line as something between Crude and Tudor or Desert.
Adding to this. The Shack tileset has fewer pieces as well.