If they were people of note the yard sale would be held at Christie's not in the street in-front of the house.
If the collection of books is of note likewise.
No the point is that a yard sale would accomplish the goal of getting rid of the stuff without maximizing profit. The only reason to hold it at Christie’s is to maximize profit.
A yard sale is maximising the profit - stuff that doesn't sell at a yard sale goes in either the bin or to the charity shop.