I'm guessing because it's such a large lot. Not so much the price but that there are so many things. I'm guessing that there is a lot of interest but they are interested in only one or two items and the rest would be dust catchers or something that they'd have to go through selling themselves.
Personally I am in that situation and I think others are too. You may want to consider splitting things - either individually or into small related groups.
Of course it may have nothing to do with that since it's just a wild guess