Retail giant Costco Wholesale Corporation (NASDAQ:COST) could highlight the impact of tariffs on business when the company reports first-quarter financial results Thursday after market close.Here are the earnings estimates, what experts are saying before the report and the key items to watch.Earnings Estimates: Analysts expect Costco to report first-quarter revenue of $67.17 billion, up from$62.15 billion in last year's first quarter, according to data from Benzinga Pro.The company has beaten analyst estim ...