[pogo]

We have a local Lego re-seller (https://bricksandminifigs.com/) which I visit occasionally. One time I spoke to the owner about the business economics. They try to buy complete kits. It is not economical to re-create kits from parts if you sort manually. When they buy unsorted Lego collections from collectors/enthusiasts, they do a limited manual sort to pull out the most valuable pieces and then they store the leftovers. When I spoke to her, I believe she said she had 2 storage units filled with Lego that aren't economical to sort further. Run-of-the-mill bricks and pieces have no value other than scrap. The value is primarily in mini-figs and rare specialty pieces like clear acrylic canopies. Obviously, kits are valuable, but only if you don't have to create them by manually sorting. Also, used kits are much more valuable if they are sold already assembled as proof that all of the pieces are included. This assembly labor must be factored into the business model.

Buying lots off of Ebay, it seems like you risk buying presorted Lego which have already been picked over for the most valuable pieces.