30 day demo on adobe.com. The 3d import is really cool since you can drop in, rotate, and paint an model is a large number of formats. It wouldn’t make sense to save it as a model since you can’t edit the model from Photoshop, but I imagine there is a way to save your textures (the painting seems to work like Zbrush).
PS CS4 Extended also has some really cool image capablities such as measuring, counting, and smart stretch/scaling (for example you can widen a landscape without stretching people that are in the image).
the basic creative suites costs the same as 2-3 apps, so if you intend on branching out at all, it is worth the investment