This might be true on a small scale, but for a large AAA-sized studios economies of scale kick in. I'm not saying it's not expensive, but beyond a certain scale

This might be true on a small scale, but for a large AAA-sized studios economies of scale kick in. I'm not saying it's not expensive, but beyond a certain scale it becomes less prohibitive. Art costs (measured in man-hours) are one of the more predictable aspects of game development, they scale well and can be outsourced easily.