Definitely legit.
But you could always take a look at Kinguin.net as well.
Started out as a guy who thought games were too expensive and bought in mass codes so he could sell at lower prices. Now it's a marketplace for people selling their games.
A month after release, I bought Far Cry 4 for 50% off. I bought Space engineers for 75% off. It is true that there is a risk that you get a scammer, but for a mere €,50 you buy 100% money back insurance within 30 days.