For unrealengine there is a completly free way to produce high-quality content with free/open source programms since unreal is using standart formats like .fbx / .tga / .png and so on for al of the content.
PGI is using Cryengine 3 so things starting to get difficult in therms of content/textures and so on. Since you need special cryexporter you are bind to the "state of the art" programms like photoshop, 3ds max , Maya or Softimage.
There was a free professionel 3d package (softimage mod tool 7.5) wich has cryexporter-support but since some months there are no infos to it on the autodesk website. You can still download it i think http://www.moddb.com...age-mod-tool-75 but i have not try it.
I know there is also a way to make something with Blender (a powerfull free 3d Package) http://www.crydev.ne...?f=315&t=103136 and with Gimp ( a powerfull free programm like Photoshop) http://www.crydev.ne...p?f=315&t=72267 but have not tryed it yet.
As Adridos mentioned i would start with the free cry sdk 3 http://www.crydev.ne...detail.php?id=4 and follow some "first level tuts" on youtube... there are tons of them.
If you have no experience with this thing you dont need Sculptingsoftware (a bit of overkill for a beginner).
Cheers
Edited by Allfex, 01 April 2013 - 02:55 AM.