So your looking for 3D software. There are many available here on ebay at a variety of prices. My suggested title for beginners would be BLENDER. Now the software itself is free from the Blender foundation. What you are paying for here is the same software on disc and it's the Disc that you are paying for. Blender is by far the easiest software to use and there a many sites dedicated to helping you learn.
3D Gladiators are great as well as Blenders own site. So if you want to get started then use Blender as a foundation to your new world of model creation. Get it free from blender foundation and get creating. The sellers here will also add a very useful help file to the disc and many other useful tools to get you going.
Maya and 3Dmax are excellent but very expensive and will take far longer to learn but great results are achievable using them. Truespace from Caligari software is very good as is software from Daz studio. However prices are steep for those on a tight budget.
I recommend BLENDER. It's free and it's great. Version 2.48 is the latest manifestation of the software and will run on any operating system.
So give 3D modelling a go. Go Blender.