Hi Jove,
Retail price calculation works on simple process. It determine your purchase price and allows you to maintain markup on the purchase price to get final Selling price.
From error, it is very clear that, system is not able to determine the landing cost (purchasing cost) for an article. There is no info record exists to relate your article to any vendor. Kindly create the vendor in the purchasing organization and maintain purchase price through an info record. Once you do the same, the retail price calculation will work properly.
Let us know if you need any further information.
Regards,
Amit