This sale really highlights the fact that there are two camps in comic collecting: people who collect books for the art (especially the cover art) and people who collect key issues. Obviously, the people buying those two books are in the latter camp.
As someone who collects for the cover art, neither 'Tec 140 nor 'Tec 168 appeals to me much. I do want to pick up some D.C.s because I don't have many, but the cover art seldom grabs me. In every auction that comes along, there invariably ends up being something I like better than whatever D.C.s I'm thinking about pursuing.
'Tec 31 is one of my favorite DCs, but I've basically been priced out of that one. (I don't buy lottery tickets, so I can't even say, "Unless I win the lottery.") Back when it was affordable, I could never find a copy with nice pages. Now I wish I'd bought a copy with C/OW pages so I could trade up in page quality.