Jörg Knappen wrote on Fri, Oct 12, 2012 07:11 AM UTC:
In Derzhanski's list (
http://www.chessvariants.org/piececlopedia.dir/whos-who-on-8x8.html )
tentative values for the Ultima pieces are given. They are calculated by
Zillions of Games and may be grossly inaccurate, but I have not seen other
estimates for them.
Maybe experienced player of Ultima can say something about the practical
values?
In addition, I recommend reading the series Ideal Values and Practical
Values
(
http://www.chessvariants.org/piececlopedia.dir/ideal-and-practical-values.htm
) by Ralph Betza. It contains lots of insights in piece values. But the
gold standard for piece values still is playtesting (between humans or in
computer play).