How old is too old?

Some good points. Thanks, everyone.

You don't forego listening to your cd's when you move to streaming, rip them to streamer internal drives or NAS. You then back up those files via something like RAID, so two drive NAS, second drive is copy of first drive. And then I have a copy of the copy via usb drive, so three drives would have to fail for me to lose my over 3.5k rips. Another possible advantage of this is cd rips may have better sound quality vs cd's with transport, mine did with the subsequent transports used after my ML No. 37 died.

Disc drives do wear out over time.  I recently went through a lot of effort to replace the pickup in my Sony XA5400ES (w/VSE mods) which is still a great sounding player.  

It’s hard to tell how much use a previously owned player has had or how much life is left in the pick-up.  So, there is a risk buying used.  Perhaps keep your search to players manufactured in the last 5 years?

Another poster recommended Esoteric which makes highly regarded disc players.  If I couldn’t get my Sony fixed I planned to get a Marantz SACD 30N which also supports streaming.

If you find a used player you like, call the manufacturer and see if they will sell you a transport. Just buy it and factor it into the total cost. If you decide to sell it for some reason, having the extra transport will make it much easier to get a fair price,

I'm of a similar age and over the last few years I have been buying my end-stage components. I have a large collection of CDs and SACDs and I can't bear to part with them. I also stream using Qobuz but there is just something more satisfying about playing a silver disc.

I recommend something like a Marantz SA KI Ruby SACD player. I have one and I can vouch for it's quality. I have owned 3 different Marantz CD and SACD players over the last few decades and I've never had a drive fail. Several years ago I splurged and bought a PS Audio Perfect Wave Transport it had 3 drives fail in 3 years. Piece of junk. The difference is that PS Audio used a standard $15 computer CD drive which was never designed to spin discs hour after hour. Marantz builds their own transports and they are designed for playing music CDs. Marantz sill makes a SACD player so you could get a brand new one if it makes you feel more comfortable.

For less money, a used Marantz 8000 series SACD (8003, 8004, 8005), is also a good candidate. I had an 8004 before I bought the Ruby and it never had a problem. There is a bunch of these from Japan for sale on eBay (I'm not sure why).

If you go with Marantz or one of the few other companies that make their own drives (Esoteric for example) the company should have spare drives for the foreseeable future. I seriously doubt you will ever need one assuming that you are not spinning discs constantly throughout the day. If you want to do some research you can try to buy a used SACD player that incorporated one of the later Phillips drives. These are basically bullet proof but if one breaks there are replacements available.

I use my KI Ruby to play SACDs and I also have a Jay's Audio CD3 MK III transport plus a Berkeley Audio Alpha Reference II MQA DAC. I have compared the two setups for sound quality and to my ears they are nearly identical. I could easily live with the Marantz player as my only rig except that it won't play HDCDs. I have a few hundred CDs in this format and I want something that will play them to their fullest potential.