Hi,
Check the below inputs ,it may helpyou to meet your requirement. Check with abaper as the development should not affect the performance.
1. Create custom transaction to update the price for the material and vendor... Approval levels has to based on the prices it should be decided by the business
2. Create Z tabel to store the informations & separte Z table to maintain the authrized user
3. Create Z transaction to approve the price
4. once it got approval by using Functioanl module/bapi update the price in the info record via background session
Regards,
Renuga.A