There are several free open-source pieces of software that might suit your needs... I know plenty of people with 3ds max who use wings to model for example... and then blender is just awesome... anyways, a short list:
Modelling:
http://www.wings3d.com/
All-in-one:
http://www.blender3d.org (or
http://www.blender.org/)
Render (renderman):
http://www.aqsis.com/
Raytracers:
http://www.povray.org/
http://yafray.org/
Sound editing:
http://ardour.sourceforge.net/ (linux only)
http://audacity.sourceforge.net/
Image editing:
http://www.gimp.org/
Video editing:
http://virtualdub.sourceforge.net/ (windows only)
http://kino.schirmacher.de/ (linux only)
http://heroinewarrior.com/cinelerra.php3 (linux only)
http://cinepaint.sourceforge.net/ (touch-up)
Anyways, that's enough free open-source software to do every part of your project without ever dealing with trial periods. There's plenty more in each topic, but those are the best ones that I've personally worked with (bar yafray, kino and aqsis as I've always used other tools, though might be using aqsis soon). Enjoy.