Check out 20FT ISO Shipping Container 3D model purchase 3D model on CGTrader for $350. High-quality mesh by cwoolley.
IGE (IGES, filesize: 6.29 MB), STP (STEP, filesize: 3.97 MB), SLDPRT (SolidWorks, filesize: 2.71 MB), IAM (Autodesk Inventor, filesize: 12.9 MB)