Ask YC: Leaving consulting to build a product. Is my consultancy worth anything?

I launched a design/programming shop a few years ago that has been reasonably successful (4-6 employees, profits, local name recognition), and I'm itching to move on to a startup that builds a product or a service.

Is my consulting shop worth anything? Do people buy web design or contract development firms? I've always assumed that the answer is no, because our value is in our people (who may or may not stick around), but a friend recently suggested otherwise.