High-Detail Prototype 3MF Design

I have a prototype that will be shown purely for visual presentation, so every surface, corner, and curve has to look production-ready right out of the printer. I need the finished file delivered in .3mf format, fully watertight and ready to slice... (Budget: €8 - €30 EUR, Jobs: 3D CAD, 3D Design, 3D Modelling, 3D Print Design, 3D Printing, 3D Rendering, CAD/CAM, Graphic Design)