That's right. I have a brand new chrome A12 6x6 back (30212) that's still sealed in its factory package. Never opened. Never used.
KEH wants $160 for an Ex version. So $200 for one that's never been out of its original sealed cradle seems reasonable to me. I think I paid over $600 for this back in the day... new from dealer, of course.
That would be $200 net to me.