Aaron had managed to buy five skill stones, of which Rick took three, and Zoey kept two. Whether Aaron wanted any for himself didn't matter to them. But for Rick and Zoey, who had successfully stolen attribute points with the stones, a few stones just weren't enough to satisfy their craving.
They had lost anywhere between five to seven attribute points in total. If they hadn't discovered that it was possible to steal them back using the skill stones, they would have gone completely mad. Especially since this wasn't the first time they'd lost attributes—months ago, they had noticed similar losses.
Rick grew suspicious of everyone who had been around him during those times, but there was no discernible pattern. The only constant was that Zoey had always been by his side when it happened.