Updated price on GBPA

Hello Experts

I have a requirement to update the price on all the existing purchase orders when ever the price on the corresponding GBPA is udpated.

We create 1000's of lines on a single purchase order which is from a catalog and when ever I update the price on GBPA i want all my existing purchase orders to get updated with the new price. I know that we can use retro active price adjustment but this will create accrual adjustment entries and transfers these costs to projects which we dont want.

We are in R12.1.3 and use only categories.

Please advise