$21 is alot for a radio knob. I was lucky to get a Christmas discount. $16 is still out of line. But then I sat back and fingered one for a minute. Coming from a manufacturing mentality, there is over a hours worth of American labor for each one. By the time you machined, de-burr, polish, paint to customer spec's, I would assume polish again, package, and with free shipping, there is not alot of meat left on the bone.
I'm doing what the .gov asked, stimulate the economy.