Does Oracle allow supplier to update all information related to BPA except prices/price breaks ?

Summary:

Our client has a requirement to allow supplier to update Agreements (using supplier portal) except the price

Content (required):

This role : Supplier Sales Representative : allow the supplier to manage agreements  and deliverables for the supplier company, but the requirement is to give the green light to supplier to update all information in the line level (description, UNSPSC, long description, UOM, ...) except the price & price breaks (these 2 informations can be updated by the buyer)

How to handle this requirement ?

Also, our client desire to link the approval BPA change based on the category (example : if we use the category Marketing = no need to approve the changes done by supplier using supplier portal, but if we have the category Transport, then an approval is required from the buyer to validate this agreement)