What Is The Cost Of Amplifier Casework?

Having built a muscled up Pass F5 clone I can absolutely assure you that the case is the single most expensive part of a power amplifier. Pass amps are pretty plain-jane as far as cases go. I used a steel 4U HiFi2000 case with no mods or extras and it cost almost twice as much as I spent on the power supply. Had I gone with the aluminum 5U case it would have made up almost half the cost of the amplifier. I look at some of these radically styled cases with pimped out dial meters (think D' Agostino), obscenely machined heatsinks (Boulder), and expensive materials like copper, and I KNOW at least half you money if going towards the box the parts are in. 

As for lots of time programming CNC machines.... Not really. I was a CNC machinist in a prototyping shop for several years. We used to make parts and guages for the space program, Pratt & Whitney, Ford, GM, Harley-Davidson, Price-Pfister, and god knows how many others. I personally machined almost all the parts for the left and right banks of the Ford V10 fuel injection system gauge and calibrated it myself on a Mitutoyo CMM. I've never seen an amplifier case that had any part that would take more than 15 or 20 minutes for an experienced programmer to program a CNC mill to bang out. Marking up the blueprint maybe 10 more minutes. That's assuming the CNC doesn't take CAD files directly. Aluminum extrusions are by far the cheapest way to make heatsinks. The only real expense is the die which is very expensive to make because it needs to be cut on an EDM from heat treated O1 steel and those things go SLOW. 

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. 

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.