I'm definitely somewhere on this spectrum. If I see dollar boxes that're bagged and boarded, I'll probably look through most or all of it. If it isn't, but it's sorted at least by title or letter, I'll go through just for my want list, so just 1-2 titles/letters. If it's totally unsorted or sorted at too high a level, though (like company), I'll probably pass them by unless it's just a single box or two, or in a situation where there may be anything in there (i.e., flea market or garage sale). I understand that it may not be worth the time/return to bag and board dollar books, but I already see them as more likely to have condition issues if they're loose, and to sort through 10+ boxes of loose, unsorted books just to find non-key run filler, or worse, to find out that there aren't any for the title(s) I want, or not any of the ones I need...I find myself more likely to just keep walking. But that's just me.