It might depend on what your needs are. Are you looking for a 3D CAD program? Are you hoping for simulation functionality? Would you be okay with just a simple drafting software?

I need software for a design office whose main target will be the aerospace industry. I would prefer software that has all simulation and manufacturing tools while having cheap payment options.

I don’t know if this helps at all but NASA has a webpage of open-source code and simulation frameworks that they use for their own remote missions – https://code.nasa.gov/