Imperial I-Class Star Destroyer (Polygon mesh 3D model) is available on CGTrader for $80. Original author: ELR-. Specs: 4972539 polys, 4408267 verts.
BLEND (Blender, filesize: 692 MB), OBJ (OBJ, filesize: 411 MB), FBX (Autodesk FBX, filesize: 411 MB)