What to know if changing the Purchase cost from 08 to another cost method

Hello.

Our business users for one branch plant within our system are inquiring about the possibility of moving away from having the 08 cost as the Purchase cost to default on POs.  This is due to the fact that the 08 cost is natively updated in JDE by several other programs (receipts, vouchers, etc.).  They want to be able to lock in a purchase cost for use in issuing POs.  We have suggested the supplier catalog as a means to accomplish this same function; however, our purchasing users have indicated that they do not want to go that route as purchasing