Because AutoSketch 10 is legacy software, you won't find a direct purchase link on modern storefronts. Here is how users typically access it today:
AutoSketch 10 was the final evolution of a tool designed to bridge the gap between simple sketching and complex CAD. Where can I download AutoSketch - Autodesk
Sites like CNET Download may host historical file listings, though these often point back to discontinued manufacturer links. Key Features of AutoSketch 10