Hiya Jason
This is the only costs for production I have ever seen in print.
http://backlotanimation.rubberslug.com/gallery/master_query.asp?SeriesID=20938
For large pics you can read, password is backlotcave1, I will change this temp password after you read this.
These prices are based on a saturday morning type cartoon.
Full blown hour or longer cartoons can run into the millions because of high priced voice actors used and lots of FX and marketing.
Prices to make them stayed the about the same from the 1940s to the late 1990s and with the advent of GC you can cut the costs by one third ,Do to the fact cels are not needed and therefore not made and in the last few years the use of computers to also make the backgrounds, You can take that one third to one half the costs of the 1990s prices.
I was told a few years ago that it costs about 10 to 100 bucks per cel to make a show that included all the stuff to shoot the show with like backgrounds, FX, ect.
So your figures are about right for the cost of a average 20-25 min show.
Somewhere between 10 and 30 grand if all the animation is CG and done inhouse and not farmed out,shows that use alot of hold type cels can do them a little cheaper do to the fact less animation is needed,Like the DBZ type shows.
Older production companys that have been doing it for awhile will be at the lower end of that scale, Newer upstart companys will be at the higher end of that scale because of startup costs.
This info comes from the book (7 Minutes, The life and Death of the American Animated Cartoon)
By: Norman M. Klein
Some of the CG info comes from some of the animators I have talked to over the years about animation and the costs for it.
Jason if you would like to read this book I can loan it to you it is full of info about animation and how it was made in the past and up to the mid 1990s, Let me know and I'll drop it in the mail to you so you can read it.
I hope this helps some.
Roy