No-one will be expecting free drinks, but probably a buffet. So I would definately find someway of letting them know that no food will be available, as some may rely on food when drinking alcohol, and can therefore eat beforehand. Some social clubs sell hot food, and all will let people take their own. As long as people know, everyone will enjoy the pary. No-one is going to think you're a miser, I think most people appreciate that things are expensive and will admire you for having a party anyway, rather than not bothering cos you can't go the whole hog. Have a lovely wedding.