Hi Marc,
Thanks for the extra info.
With a budget like this it's going to be very hard to get this done!
As I said rendering alone will eat up your entire budget under normal conditions.
An option is to find someone who renders it for free:
http://garagefarm.net/free_rendering.htmHere you can have work rendered for free on some conditions.
Since this project is meant for fantasy novels I take it that it won't pass for being an educational project, so it's likely these guys won't render it for free for you, but you'll never know and can always try!
Another option is to find someone who does the work for free so you can spend all on rendering, but then I'm not your guy

Though there's of course a chance someone's willing to do this purely for fun and exercise, but that would also mean that you probably can't impose deadlines and demand a lot of taylored work.
This can affect quality of the work and is a reason why some ask money for their work, because they take it serious.
Of the 2 options I described I'd investigate on the cheap rendering one as having machines sweat for free is better than having people sweat for free

That garagefarm is cheap anyway.
Other renderfarms: PixelPlow and Ranch Computing Farm.
Before you can make a good estimate you'll need to spend some of your budget on scene development.
Someone needs to make your canyon and tell you that it renders at 2 frames/hour in 1280x720 resolution (fast!).
If you need higher resolution then rendering takes (a lot) longer. Lower res is faster of course.
From that scene you can estimate/calculate the time for rendering the total animation which you can then use to estimate/calculate the costs to have it rendered on the farm.
So I'd like to suggest to give it some thought and get back with some more details on output and references here to see what we all can mean for you.
Martin