Check out Cave Rock Pack 1 - Rust Low-poly 3D model on CGTrader for $12. High-quality mesh by wernie: 13336 polys, 20004 vertices. PBR, Textured, UV Mapped.
OBJ (OBJ, filesize: 935 KB), TEXTURES (Textures, filesize: 22.7 MB), 3DS (3D Studio, filesize: 497 KB), BLEND (Blender, filesize: 1.92 MB), FBX (Autodesk FBX, filesize: 1.1 MB), DAE (Collada, filesize: 830 KB)