Should I list all my classical CDs?

I would keep them, personally. Things change and you might want CDs to use in the future. 

Selling collections may prove not a good idea in the future. But if sold you will get some funds for more lp's.

G

If you want to keep the collection together, give it to a library, or someone you know, or sell it for a price that you know the buyer will buy it for themselves and not just resell them really cheap.

Hi Simao,
I'll be interested to hear what you decide. I have about 800 mostly classical and jazz CDs that I've ripped to both a Sony HAP-S1 and to an external hard drive for backup. I haven't played a CD (except for some comparison purposes) in many years and, given the convenience of the Sony, don't see myself using them. Right now, the CDs just sit on shelves as part of the "decor" in my living room. I should donate them to a charity such as the public library or maybe Goodwill. But being pennywise and pound foolish, I need to inventory them in order to take a tax deduction, which I've been too lazy to do. If a calamity occurred and the Sony, the hard drive, and the CDs were destroyed, I'm lucky enough to be able to switch to streaming services.

To answer your question more succinctly (and rhetorically), why not just take them to your public library, which will make them available to people who will enjoy them?

I would first check and see what they are being sold for used on Amazon.  You might be surprised how much the prices of Classical CDs have increased.

I have found many CDs that I paid $11.98 for several years ago, from Amazon, are now offered for sale at over $60 used.

Cheers