Try this:

=IF(A1=30000,"A",IF(A1=20000,"B",IF(A1=10000,"C ","Not an EDPR
Acct")))

I have assumed that the cell with the monetary value in is A1 - adjust
accordingly.

Note that your description does not cover what to do when the cell
contains exactly 10,000, or 20,000 or 30,000 - I've assumed that these
are part of the higher range.

Hope this helps.

Pete