Pricing up an animation is a tricky thing, as the cost of a piece can vary considerably depending on a multitude factors...
How long is it? How complex is it? Do assets need creating? Is there a corporate style to match? Does a script need writing? Does it need a voiceover? Will it have music? Will there be any filming? Will it need 3D modelling? How quickly is it needed?
The chances are (unless you work in a creative agency) you won't have the answers to all of these questions, indeed not everyone realises what goes into creating animations.
It may be that you don't know what you want yet, that's fine, I am happy to help you on that. We would need to have a discussion about what it is you hope to achieve through creating the piece and I would then advise on the best way to proceed within your budget and timescale.
Usually I quote per project, but occasionally on jobs where things are changing all the time, or where it's simply impossible to calculate how long the job will take, it's better to charge on a flat day rate basis. I am happy to work either way.
As with all things, the budget and the deadline will dictate the level of finish. If there is only a small budget to work with, there is always something that can be done, it usually just involves taking a simpler approach and being realistic about what can be achieved.