NEW YORK (TheStreet) -- Costco Wholesale (COST) - Get Report, the largest U.S. warehouse retailer, seems to never get cheap. This suggests that its investors are not as price-sensitive as consumers who shop at its stores. But the one thing both camps have in common are that they seem to appreciate value. And that's something Costco, which reports earnings results Thursday, knows how to create.

Costco shares are up more than 7% in 2015, besting both the Dow Jones Industrial Average and the Standard & Poor's 500 Index, which have gained just 2% each.

Equally impressive, shares of Issaquah, Wash.-based Costco have also outperformed the 2.7% gains in the SPDR S&P Retail ETF (XRT) - Get Report. And that's where investors might begin to worry. The latter houses more than 100 retail companies in its fund, including the likes of Amazon (AMZN) - Get Report, Kroger (KR) - Get Report and Wal-Mart (WMT) - Get Report.

All told, these retailers have an average trailing price-to-earnings ratio of 22, which is in line with the S&P 500, compared with a trailing P/E of 30 for Costco. That would indicate Costco's shares are expensive. What's more important to consider, however, is the word "expensive" doesn't prevent the stock price from going higher.

And like the old consumer axiom, "You get what you pay for," investors have consistently gained from Costco's above-average price. Take a look at the chart.

COST 10-Year Total Returns (Daily) data by YCharts

COST Return on Equity (TTM) data by YCharts

In the last 10 years, five years and three years, Costco investors have received stock gains of 305%, 181% and 95%, respectively. And each have exceeded the respective gains of both the Dow Jones Industrial Average and the S&P 500 during those periods.

Investors are also paying for Costco's ability to return value to investors, based on its trailing return-on-equity of 18%. Take a look at the chart.

Return on equity explains how well a company's management team performs. This is because it tells investors how the business is using invested capital to increase shareholder value.

In this case, Costco's ability to generate wealth for its shareholders exceeds that of several prominent retailers in the SPDR S&P Retail ETF, which has produced an average return on equity of 15%. Couple that with its five-year stock performance of 23%, compared with 181% for Costco, it's the investors who focus solely on price -- and not value -- who have missed out. 

For the quarter ended February, analysts expect earnings to climb 12% from last year, reaching $1.18 a share, while revenue is projected to be $27.7 billion, up more than 5% from a year earlier.

With U.S. retail sales up 3.3% from last year, according to the U.S. Census Bureau, Costco, whose earnings are projected to increase by more than 10% annually during the next five year, should benefit. Coupled with the stock's consensus buy rating and annual dividend of $1.42 a share, the shares are never cheap for a reason. Current shareholders love it that way.

This article is commentary by an independent contributor. At the time of publication, the author held no positions in the stocks mentioned.