If your Scan2CAD usage is specifically for turning maps into CAD data, QGIS is the superior free alternative. It specializes in georeferencing and digitizing raster images.
3.2 Potrace (command-line)
(PostScript/PDF to DXF):
Scan2CAD is widely considered the industry standard for converting raster images (like PDFs, JPEGs, and scanned blueprints) into editable vector formats (DXF, DWG). However, its steep price tag often pushes hobbyists, students, and small businesses to look for cheaper solutions. scan2cad free alternative