My experience:
I loaded my collection on discogs ( pros: I finally have a true report on what I have, approximate values, dupe, what I care or not, cons: time consuming)
then I sold on discogs the most valuable records I didn’t care, mostly audiophile pressings, because I had originals or in mosaic Lp sets ( pros: overall a little gain from what I paid them, a part some classic rock records out of print that fetched good money, free space at home. Cons: packaging cost, PayPal and discogs fee, dealings with some buyers not very friendly, shipping companies and post offices)
Later I putted on sale dupes and Lps I didn’t listen to anymore ( very very little gain but I got free space)
Later on I putted on sale cds box sets and cds, the real gain on a single cd is around 3,50€ considering mailer and fees.
So far I sold all the audiophile pressings, most of the vinyls, some cd box sets and 30% of cds I have on sale.
I have considerable free time at the moment that allow me that, because it’s some sort of part time job and I understand people who don’t have time nor desire but for me it’s another way to listen to music when I have to check records and take care of my collection I mean it’s part of the fun of collecting records and having some money on PayPal account helps.
I have to say that I don’t buy records anymore few exceptions a part, so I am basically trying to consolidate my collection I even trashed some damaged records that were unlistenable and I am very liberal about the concept .