Publish the age of your component when selling (let's discuss)

I've noticed that many sellers don't publish the age of the item or items they are selling on Audiogon.  I believe it should be required that the age or original manufacturing date of the item being sold be clearly stated.  Some do but many don't.  Sometimes you can see the manufacturing date on the back of an item should the seller post a photo clear enough to see it but a prospective buyer shouldn't have to find it out that way.. What is the fear here?  This is especially important when it comes to sources such as DVD and CD players.  No matter how great the CD player may have been at the time, an 8-10 year old unit (let's face it) is worn and the DACs are no longer state of the art. You may think you have a piece of gold but the transports wear and again the DACs are antiquated. 

Opinion now:
I believe that many of the CD players on sale now that are say at least 10 years old are over priced.  To back up what I'm stating here, out of sheer curiosity and with a little extra cash I had, I very recently bought a brand new Onkyo C-7030 CD player for $200.00.  Got it home and in a matter of a few days, OMG, the overall sonic fidelity and extreme detail is produces when playing decently recorded CDs is nothing short of amazing.  Why would I purchase a pre-owned $1,000.00 player when this Onkyo sounds just as great?  I know this is a loaded question and may not be too popular but would love to hear what the members think.  No offense to anyone's machines.  THANKS.