What to do/

You will spend an ungodly amount of time selling them piecemeal.  That is your main consideration.

Most DJ’s are hard on records and equipment. Count the number of records and figure a dollar apiece for them and try to sell as one big lot. But don’t expect to get a thousand dollars for a thousand albums.
At a garage sale about six years ago, I bought roughly 975 CD’s for $150. I kept about a hundred to fill in voids in my collection and sold the 875 for a hundred dollars.

YRMV

Oh,

And as far as the equipment, you can get an idea of the value of each piece, by seeing what others are asking on some DJ specific sites and or EBay.

All the best.