It is best to spend a lot of time with the demos. When I purchased Vue5 Infinite there was no demo, and I needed the application to create digital art for representation in a Santa Fe, New Mexico art gallery. Although I've managed to produce some complex artwork with Vue, the road was fraught with many beta potholes! Vue is certainly better than when I purchased, but it still has serious bugs (latest, alpha maps in 2 tier plants getting hosed when creating a new species (actually a variation) of plant from an existing one). I think e-on has cranked out over a dozen patches since release still has problems.

I think Carrara 5 Pro is the best bang for the $$. Obviously Maya 7 and 3D Studio Max 8 are powerhouse applications, and if you are planning on producing for the movies then go for it. However, as mentioned by others, very steep learning curves for both.

Carrara and Vue are both easy to use, although I think Carraras interface is now way better than Vues.