Is Duolingo's growth potential worth the high price? Let's see whether it's too late to join the green owl's party.Language-learning expert Duolingo (DUOL 3.73%) has been crushing it on Wall Street lately. The stock is up by 180% since the start of 2023, lifted by a steady stream of analyst-stumping earnings reports.However, the stock is soaring on some very lofty valuation ratios. Trading at 208 times earnings and 15 times sales, many value-minded investors would give Duolingo one quick glance before backi ...