I stopped selling 9000's at least 3 years ago. Peter is quite correct about the cd servo board problem (which is repairable) but omits to mention the little plastic widget and spring that is the cd clamping mechanism which is NOT repairable, no longer available as a spare part and will undoubtedly turn it into a big radio/cassette player!
As a trader, I am bound by law to provide a reasonable warranty and with that in mind it is simply not worth taking a chance with the BC9000 as it can only p*ss customers off when it fails and is un-repairable. It is not worth taking the chance.
They are worth £50-£100 for canibalisation for spare parts but that, I am afraid, is about all.
Similarly, CX50's and CX100's ALL get foam rot, there is no doubt. Again, as a trader, the only safe option is new woofers or "the mucky job". They are worth £50-£100 at very best and the skip otherwise.
Sorry if I have offended but this is the real world.