It is not a problem to offer products that are already offered by other vendors on Avocadostore. In this case, the product creation is omitted and you only have to place your offer on the existing product.
To do this, search in the shop backend under Products – New product (Neues Produkt) for corresponding product names, brands, keywords, EAN/ISBN or SKU. Select the button "Offer now" for the respective product that you want to offer and fill in the corresponding offer data. As soon as you have saved your data, your offer will be available and will be in direct competition with other suppliers.
Which offer is displayed first depends primarily on the sales price and the shipping costs. The cheapest offer will always be displayed first.