Ten shares bought at Costco's IPO would now pay $1,329 in dividends each year.On Dec. 5, 1985, two-year-old retail company Costco Wholesale (COST +0.17%) went public at $10 a share. In its first earnings report filed the following January, it announced sales of $134.5 million.The report was staggering for two reasons: first, because the fledgling retailer had almost tripled sales while turning profitable over the last year, and second, because the report only included the quarter up to Nov. 24.Forty years l ...