2D Renders to Printable STL Models

I have a collection of 2D renders that I now need turned into solid, print-ready 3D geometry. The final purpose is 3D printing, so every mesh must be watertight, manifold, and correctly scaled. I’m aiming... (Budget: £20 - £250 GBP, Jobs: 3D Animation, 3D Design, 3D Modelling, 3D Print Design, 3D Printing, 3D Rendering, Blender, Fusion 360, Solidworks)