No cost rendering software
3D rendering is no longer the expensive affair that it used to be. Now anyone with a decent computer and the internet access can have free and yet powerful programs for making renderings.
Kerkythea is a capable renderer can that produce very good result. It comes with an easy to use interface.
Yafaray is the new development of Yafray. It is a competent renderer that can be run from within Blender 3D.
Indigo is a free and physical-based rendering. The rendering it produce looks exactly like photos. However, it renders very slowly.
There are many more free renderers.