Proverbs 5:10
Lest strangers be filled with thy wealth; and thy labours be in the house of a stranger;
Whores are expensive. At best, they want you and your money; at worst, they want your money without you. Even when they do not take your assets or income directly, they are expensive to entertain and support. If you needed another reason to avoid them, here it is.
King Solomon in this proverb gave his son another reason to stay away from the strange woman (Pr 5:3), which is any woman he had not married – whether prostitute, whore, or adulteress. It costs a lot to buy their favors or keep them happy; his assets and income would go to those outside his family, even though they do not provide any lasting benefit.