I have to vent because this just seems so silly....I keep reading threads where people defend their decision to have a cash bar by saying, I don't wan't to fund people getting crazy drunk (or something like that).
How is this a reason not to have an open bar? Do you not think that your friends can control themselves? Just because an unlimited amount of alcohol is available doesn't mean someone is going to lie down on top of the bar like it is spring break and have the bartender upend a bottle of tequila into their mouth.
This reasoning just seems ridiculous to me. To say that someone won't get as drunk because they have to pay for it is asinine. Have you never seen someone get completely wasted at a bar? Who is paying for that? I'm guessing they are paying for it themselves.
Host what you can afford, but don't use peoples drinking habits as an excuse! I doubt people are getting your invitation and thinking, yay, Jane and John are getting married so we can get wasted on their dime!!!!
Also, if you only want or can only afford beer and wine, that's fine too! But don't say you are doing it just so people don't get drunk. A little lesson in alcohol, it's not what you drink, it's how much you drink. Most reasonable adults are not going to go overboard just because someone else is paying for it.
We have to assume our guests are going to be well behaved... if you think they are going to act like embarassing, overgrown baboons, then maybe you should rethink your choice in friends.