Is it a good idea to buy CD players over 10 years old even it is a reliable brand?

From how the question is phrased, I'm sure that Faust understands that disc spinners can break down, so I'm definitely in the camp of being reluctant to buy these -- for one thing, you just simply don't know how many hours are on it. I had a wonderful Proceed PDT3 that just conked out a year ago after 18 years of use and I had used it heavily! And it was the transport mechanism and could not be serviced. So as others opined, for more expensive disc spinners make SURE that they can be serviced.  
  I replaced my transport with a media server.

Comment #2: I don't think you can assume that players today are better than those of 20 years ago at a roughly similar price point. Companies like Madrigal, Mark Levinson, were driven to produce fantastic players in the new field. Today? I'm not sure they are and I've heard mass market players, such as a Marantz I recently auditioned ($400), that had all that digital hash jitter that we thought should have vanished by now....

It sort of boils down to pride of ownership. A used Esoteric is a nice piece of gear that looks and feels like a fine instrument. You will appreciate the quality every time you use it. I tend to do the same thing as you're planning - I buy nice high quality used gear that I can afford. In fact I don't think I have anything in my system that is less than 10 years old. A couple years ago I went to AXPONA and concluded that my system can compete with almost anything except the super high end setups. I'm not sure we have actually come that far in sound quality between the top end gear of 20 years ago and today.

I picked up a used Esoteric SACD player a few months ago...best buy I have ever made in audio!! The player is absolutely amazing sounding and easily beat out many other far newer designs. I was looking at a used Marantz at the time, also a very nice sounding piece, BUT the Marantz was not being supported anymore. So IF the transport or laser failed, I would have been out of luck with the Marantz. That is the main thing to consider IMO, when looking at an older digital piece.

I'm glad the topic of older CD players appeared here because a sentence from the current "Stereophile" review of the (very) costly Gryphon Ethos player caught my attention. Jason Victor Serinus quoted the company's sales director (Rune Skov) thusly: "That's why the lifespan for a Gryphon product can be 10-15 years." Disconcerting for a product at that price point, though the Gryphon rep didn't specify how many run hours that time period represents.