When the 360's new dash is launched, it'll cost you nothing to build an avatar. It'll cost you nothing to customise it, either, so if you throw on the wrong coloured pair of slacks, relax! Just change them over, no questions asked. But what about the future? VentureBeat asked Microsoft's John Schappert whether Microsoft were going to introduce microtransactions for the avatars, and got this response:
That may be in the future. In the near term, we want to launch these with great customization and a great library of accessories this fall. I think there is a lot more we can do with them. You will see us continue to add experiences that make use of the avatar. Our goal is not to create a sterile environment where you move furniture around. It's about how can we make our gaming experiences better.
In other words, bet your ass we'll start charging for avatar customisation, as soon as marketing gives us the green light. As an aside, note he manages to slip in a dig at Home, which isn't easy when the question has nothing to do with it!