I see it slightly differently. We (and I mean we) cook 95% of our meals from scratch. Therefore the number of pots and pans used is roughly the same whether there are only the 2 of us, or with our daughter, or if we entertain. The only thing that changes are plates, cutlery and glasses. And the latter is much more economically washed in the dishwasher than regularly bought after shattering in the sink.