Plenty of dealers out there who buy whole collections
My singles collection went to Pat Brady 15 yrs ago and I was very happy with what I got - I choose him because he was the closest dealer to me at the time
Still got my albums and 12” collection for a rainy day
So you either get rid in one full swoop and take a hit on the mark up for dealers or sell individually if you have the time which means all your big ticket and expensive items will fly and you’ll be left trying to shift whats left with people haggling and eventually eBay ! Where you will have to pay the fees in the end !