Investors with an interest in Financial Transaction Services stocks have likely encountered both Corpay (CPAY) and MasterCard (MA) . But which of these two stocks offers value investors a better bang for their buck right now? We'll need to take a closer look.Everyone has their own methods for finding great value opportunities, but our model includes pairing an impressive grade in the Value category of our Style Scores system with a strong Zacks Rank. The Zacks Rank favors stocks with strong earnings estimat ...