Psikus
Explorer
Or the fact that Studded Leather gives you 13 + dex for 25 gp, but Ringmail gives you 13 + half dex for 35 gp? So basically you're spending 10 extra gold for armor that only half as much dex bonus.
It's a bit situational, but the Ringmail beats Studded leather for characters with Dex lower than 10 (since Dex penalties are also halved).