What Is The Cost Of Amplifier Casework?

Speaker Cabinets are the greatest cost to the speaker it self.  Dont know much about casing but honestly it depends on the compelxity of the case and the materials used.

What are the chances of a manufacturer getting the internal amp design to sound right if they can't get casework that is functional and looks good?  It would be like a songwriter saying the bridge section doesn't work, but the first and second first are solid.

I don't think the styling of the chassis has anything at all to do with the quality of the stuff inside. Plenty of great amps are packaged up in plain, well built, simple chassis. I think a chassis should be well built, but pimping the thing out with metal accents, ornate dials, big fancy fasteners, and gleaming finishes is just eye candy that has absolutely nothing to do with the function of the thing. I don't think it says anything at all about the quality of the sound. 

I say styling exudes quality...surely it must be wonderful if it looks that way.   I strongly suspect lots of people buy the styling even before listening to the black box.

It exudes quality... In the machine shop they contracted to fabricate it. I'm sure people buy stuff based on how it looks. McIntosh doesn't stick those giant dials on everything because they tell you vital information. They look cool. Most people don't understand what's inside the box or what it's doing so manufacturer's try to communicate something about it through the box itself. The form has almost nothing to do with function though. Speaker cabs at least do something functional according to their form.