[AccessD] Runtimes - Preferably AccessXP but 2003 if absolutely required

Can anyone give me "just the facts ma'm" for what I need to buy to do
runtimes for a single site, IOW 40 machines all at the same location.  All
machines are Windows 2K or XP.  The application uses automation to do mail
merge.  Also automation to use Outlook.  Outlook uses exchange server if it
matters.
 
The client currently has a mix of office 2K and XP and it causing headaches
getting one version of the application to work on both versions of office
everywhere, every time.
 
I need to know the cost, how to get ahold of it etc.  The Microsoft site
runs you around and around (trying to avoid the cost issue I assume).
 
John W. Colby
Colby Consulting
www.ColbyConsulting.com