Printable STL Product Prototype Design -- 2

I have a new product concept that needs to move from sketch to a clean, watertight STL file ready for 3-D printing in plastic. The model has to respect common print constraints (no non-manifold edges,... (Budget: ₹600 - ₹1500 INR, Jobs: 3D CAD, 3D Modelling, 3D Print Design, 3D Printing, CAD/CAM, Fusion 360, Product Design, Solidworks)