Thought mismatched Pyrex lids at estate sales were free extras, turns out I've been paying $2 for trash
Watched a guy at a Saturday sale in Cleveland pull a lid from a dollar box and check the number stamped on it against the bottom of a bowl before buying. I've got a cabinet full of lids that fit nothing and I never once thought to just read the numbers.
My grandma had this whole drawer of nothing but lids and every single one was for a bowl she had already broke or given away. She would still make us dig through it every thanksgiving looking for one that fit the mashed potatoes bowl. Half the time we just gave up and put foil on it. That drawer outlived her and I bet my uncle threw the whole thing in the trash without even checking.