Costco's amazing business continues to justify a premium, even if the shares now look close to fully priced.Costco Wholesale (COST 0.01%) shares have been on a strong multiyear run, but have pulled back slightly recently, making it a good time to take a look at the stock.Investors will get to see the retailer's fiscal fourth-quarter results tomorrow. The company already reported net sales growth for the period of 8%, previewing what's likely to be another strong quarter for the wholesale retailer. The wareh ...