Hi Vijay,
Hope your are doing great. I guess the best way is to add an approver/group to the approval flow in any case for all the CAS#'s where you have multiple suppliers for the same item.
There must be a logic behind having multiple suppliers for the same item, especially with the catalogs, and based on that logic one could control the visibility of that item to the different departments/cost centers etc. You may also be able to build and add approver logic with a lookup file based on the CAS# and upper limit for the unit price. For a given CAS# if the unit price is above a certain price thats predefined in the lookup file, it add that additional approver.
Regards
Vilas