First off, thank you for the compliment I_Batman. Without trying to get "churchy" or "preachy" as some may put it, I would just like to point out my abilities are, in fact a gift from God, just like everyone else's abilities. Whether it be cooking or flying a plane or being a craftsman with wood.
I won't have to buy any new software to build units for CivIV that I am aware of. I have Rhino3D, 3D Studio Max 6, Adobe Photoshop, Jasc PSP 7, Deep UV, Deep Exploration, and Deep Paint 3D (which is really cool, you paint right onto the model itself). In fact, the units I build and animate can be used in CivIV, providing Firaxis allows us to add our own models with the SDK. Although, I would have to greatly reduce the polygons in my models for CivIV.
As for costs, you are in the ballpark I_Batman. I was fortunate to be able to pick up educational versions of 3DS Max, Rhino and the Right Hemisphere series (Deep Paint 3D, Deep Uv, Deep Exploration), so my costs were lower.