Why are equipment racks so expensive?

It is child's play to make a very functional rack. Threaded rods with painted PVC pipe spacers and large maple butcher block cutting boards. You can even buy fancy feet for the bottom if you like. I would use casters. Makes the rack much easier to move. Cost? Maybe $500 at the most. 
I would much prefer spending the money on a new cartridge rather than a rack. Many of them are flimsy. The only equipment that needs isolation is the turntable.  

@ozzy62 , lay instinct is rubbish. How the f do you think an F22 would fly if electronics were sensitive to vibration. A targeting computer has a lot more to do than your silly DAC. The Russians were using tube electronics in their airplanes up to the early 70's. Worked just fine. You guys are hysterical. Knock yourselves out.