Animating rigged 3-D models

I’m currently working on a project that requires a variety of CGI / 3-D objects to be animated, and am researching a range of freelancers and their work. We have a number of pre-existing 3-D items and landscapes from [login to view URL], and need them animated (with each animation lasting approx. 10 seconds) Below are some examples: Before commencing work, I'll need an estimate of the time required and the cost of animating the following items: - A Tyrannosaurus Rex, standing idle then roaring. - A smoking volcano. - A chariot, charioteer, and horse – moving as if the horse was galloping. - A humanoid Robot, walking. (Please not that that we're still in pre-production phase, and that the workload and budget is yet to be finalised)