What Do You Keep?

I'm not having too much trouble disposing of my books. Cookbooks--keeping only the functional, and I have almost decided having several years of Cooking Light is a Dumb Idea. Fiction--keeping only what I have a strong attachment to. THe same for the children's books, and also keeping only the stuff that's really out of print. However, I have a lot of vintage etiquette and advice books that I'm on the fence about keeping. Logically I should ebay them, and once it's done I'm pretty sure I won't miss them, but I still feel conflicted.