The 'Suppliers' app by CloudCart allows you to add a supplier from whom you take your merchandise, to assign specific suppliers to specific products as well as to compare the supplier price to the one in your store.
After installing, click Add supplier. Subsequent supplier settings are straightforward: After the settings, you need to add the products for the specific supplier:
Then you add the products delivered by the specific Supplier:
This way you will be able to choose the most advantageous supplier from whom to order the goods.