You could catalog your collection on discogs and then potential buyers can both check it out and see values directly. It will also allow you to judge offers. The discogs app is very easy to use (direct barcode scanning for example). Clearly it will take some time but less than I think any other method
Record collection sales addvice
I have been considering selling me record collection and down sizing as I approach retirement. I'm not interested in selling individualy or piecemeal. So as a potential buyer of a 2000 record, record collection what information would you want to know other then the name of the albums. should I list all the albums, condition of each individual, pressing numbers, pictures of each, etc? the more information I know will glean better response but I have to think of the time involved in cataloging every individual record. so what is the minimum you'd want to know? I would obviously include the pressing numbers for rare or potentially collectable records.