Hre you go with a little back story...
I network with card show dealers / card shop owners who don't want to mess with the bulk of large collection buyouts. The last one had 60K cards in it. Once they have pull what they want for themselves, they will reach out and let me know. I will take a look myself and if I see value in it for myself, I will either offer them a set price for all of it or I will offer to sell it for them. Before I sell it, I will do a high lever pass pulling aside anything that I want to look at closer for my own collection or TCDB inventory. I try to move fast as I don't want this stuff sitting around all that long especially if the person who offered it to me is waiting on fund after from the sell of the lot.
To get started, talk to some of the dealers at card shows, ask if they are local and if they have bulk that they are trying to move...you will be surprised to find out that many of them have loads of cards in their basement, garages or storage units and they just don't have time to get to it or just want it out of there. For example, I ran into a guy this past weekend and bought some Heritage Chrome cards from him...he said that he has more, and we are meeting up on Monday...can't wait!!