But it impresses me that it is, to a certain extent, a mean spirit that counts the cost in asking a friend to stay to a repast, to spend a night or a week.

It is your duty to have things so nice every day, and always, that you cannot be too much "put out" by an occasional guest.
When you invite your friend to make you a visit, explain that you live quietly, and that he will find a warm welcome.

Then give him just what you give John, and make no apologies.

Above all, do not let him feel that any additional labor caused by his presence throws the whole course of the household machinery out of gear.

Do not invite to your home those for whom you have to make so great a change in your daily life.