Complete Consumer Product CAD Design

I already have a solid CAD model of my consumer product, but it was built for a slightly different purpose. I now need it refined so the geometry, tolerances and internal layout support a brand-new feature set... (Budget: $30 - $250 USD, Jobs: 3D CAD, 3D Design, 3D Modelling, 3D Printing, AutoCAD, CAD/CAM, Fusion 360, Solidworks)