They are.
You can even get them with automagic balancing built into the rotors.
There is some sage advise around here suggesting that you at least get one new enough to still be serviceable (ie not obsolete according to oem)…Separation Anxiety (mechanical) if I was to guess.
I’ve know I’ve got two washing machine sized Beckmann’s (JB-6 series) that I can’t spin simply because I can’t get parts for them.
I’ve also got an even older Sorvall that is still rotating/refrigerating that I need to find a reason to have on site…we are running out of space
I think we paid $2k, $100, and $0