For customer
- Add new product (or edit product)
- Tick on we sell column
- Select Customer and fill in the cost amount
- Click on Add Customer to add multiple customer for different cost
- If the customer is not in the list, learn how to add a new customer
For Supplier
- Add new product (or edit product)
- Tick on we buy column
- Select Supplier and fill in the cost amount
- Click on Add Supplier to add multiple supplier for different cost
- If the supplier is not in the list, learn how to add a new supplier