Check out UFO Flying Saucer 3D model on CGTrader for $48. High-quality mesh by AhearnART3D: 59648 polys, 59938 vertices. Textured.
MAX (Autodesk 3ds Max, filesize: 4.8 MB), OBJ (OBJ, filesize: 5.07 MB), FBX (Autodesk FBX, filesize: 2.77 MB), MA (Autodesk Maya, filesize: 3.38 MB), 3DS (3D Studio, filesize: 2.01 MB)