Not only have I gotten this question a lot but I myself struggled with this one for my own wedding; so I am going to share it with you and I would love to know your thoughts.
My cousin's daughter is getting married and she and her fiance are paying for most of their wedding; they are definitely on a very tight budget. They really want to be able to invite all of their friends and family as well their single friends with a "guest." She asked me if it would be acceptable to invite single family and friends but not include "and guest" on their invitations? Her fiance feels like they should definitely allow wedding guests to bring a date but she feels like if they do this than they will not be able to invite other people because they will now be obligated to let their single friends bring a guest that they can't afford.