How long's a piece of string? You could have a logo on a plain white background with a slight zoom and a fade in and out... or it could be something like the idents for Disney, Paramount or Pixar.
I do a lot of logo animations but they're all relatively simple, clean minimal animations... not as fancy as the majority of ones on VideoHive. They probably only take me about half a day including revisions, so I charge around $200, more if they want an outro or lower third to go with it. I've done very simple ones for $100 and slightly more complex ones for $500.
Here's one that I think I charged $250 for including a simple lower third to give you an idea. I think it took me round four or five hours in total, including revisions, rendering, delivery etc etc.
It's not going to win any awards, but it's pretty clean, stylish, simple stylee... and it does the job.
I guess the best option would be to work out how much you need/want to earn per hour and then apply that to the estimated time it will take and provide a package price that includes revisions and maybe some stock music. If you've done animated logos before then you should be able to estimate the time it will take based on what's required... if you've not done animated logos before, then it's hard to say. I guess you could do with more of a "what's it worth to the client?" approach.
Another option is to see if you can find out what other people are charging, compare the level of quality you can deliver and price accordingly.