“Logo change is not a trivial undertaking. How much do companies typically spend when designing a logo? In my past life, I've working in the advertising industry and I know there is no easy answer. In fact, I've looked at various trade publications hoping for some quote/reference on this topic. No luck so far.”
Right, Mike; it's not easy to answer – and you won't find much good reporting on it. (The press, in fact, is drawn to stories of tens, indeed hundreds of millions in costs of "image change," based however on retail format changes or on advertising media expenses incidental to rebranding, where rebranding planning and design costs themselves were comparatively small.)
This is from Tony Spaeth's Identity Works, where the full discussion is available.