Digging through the logs (there are a lot of them!!!), I found a JAVA stack dump that appears to be an authorization issue for a database. Not sure if VC database or CBM database (stack dump doesn't show any actual database in the "junk" it spews...).
Logged on to CBM via web page as "super admin" - still failed with same problem when I attempt to set rates.
However, logging on as "super admin" to vCenter client, and accessed through VC plugin allowed me to access the "initial rates" screens.
I'll try to determine which database later - and use VC plugin for now. Thanks to all who responded.