I see all these people who set up commission openings for a bit of extra cash (perhaps even a living) and have thought about giving it a go myself.

The catch is I'm a 3D modeler for objects in games. So far, only for Team Fortress 2 on some unreleased mapping projects. If I finish them off and release them for free on a mappers website, would it be too farfetched to offer my services for money? Instead of drawing characters for an image, I could model a prop or piece of scenery for someone's map.

Perhaps the 'market' is a little different and I should be asking on a games site but commissioning seems so commonplace, I figured I'd get better advice on it here.