Good and (relatively) cheap Ada code browsing software?

[maestroff@hotmail.com (Mike)]

I've been looking for an IDE or similar software tool that would let
me trace through some complex and badly documented Ada code I have to
work with. You know - click on a variable and find out instantly where
it was created and were else it was used. Or click on a
function/procedure name to see what else it calls and what objects it
contains, etc.

I did find a program that does this and does it very well -
"Understand for Ada" by STI. I'm currently evaluating it and it does
everything I need and more. However its also $9000 for a single
licence. Before I try to convince my boss to shell out that much money
I was wondering if anyone knew of any other programs with similar
functionality that cost less. And if they aren't quite as powerful as
UforAda that is fine. Or is STI charging that much because they know
they have a monopoly in this area?

Mike