Why is a busted old cat worth $200?

[NTIman]

I've been told that most aftermarket cats don't clean very well, and the post cat 02 sensor will turn the check engine light on, even if its new.

I'm not sure about that, we pretty much only deal with the $1500 Toyota cats when replacing them, and its rare that theres a problem with the converters anyway.

But yeah, platinum and palladium.