Blender - Free - Books are released on learning it
TS (4.0+?) - in the 4 or 5 hundreds - Documentation present (books/net)
TS 1 or 2 - Free - Documentation (somewhere...)
Lightwave - supposedly around 2k dollars - Lots o' books/web sites
Maya - depends on package (free, 4000, 9000 I think) - Books and internet
Milkshape - free/shareware - Quake model design software, documenation available
3DS(max) - 1000 - 2000 (around) - Documentation (plenty)
Bryce 5 - ? - landscaping software
Terraform - free/shareware (20) - landscaping software
Softimage XSI - a few thousand - Documentation available (but rarerer than LW/MAX)
I'll edit the list as soon as I get better statistics and such...
By the way, I've used Lightwave and Truespace and Blender... out of the three I considered Lightwave the most "fun" (powerful), but Blender was generally easier to understand... (IMO)
And lastly, to convert models from anything other than TS (formats) to pof you need to use DeepExploration (or 3dexploration)