The lots may be just a bit too large to be easily digested by bidders, such as that "big DC lot," which has quite a variety. Then again, -I've- had trouble shedding duplicates or unwanted side items from eBay lots, unless I give them away -- and that doesn't always work. So I may be affected by that.
Lash LaRue has noted on the Old Boards that a sizable run under one creator (or team) on a book is pretty much the optimal eBay lot: not too short as to take up excess overhead in listing or bidding, not too huge as to take in clearly unrelated items.
I fear that some of these runs are a bit short for that purpose. Selling several of them as a larger lot increases the chances of some run lying outside one's interest.
O'course, if Rob is primarily wanting to get these out of his condo, that's another story. And his 50 percent RKMB discount is remarkably generous.