Understatement of the century: Weddings are expensive. Besides cutting down on the guest list (if you haven't been in touch with someone for the last three years, you figure you're not that close anymore) and booking less hours with the photographer (friends can take snaps of the late-night dancing), you're looking to save money on the catering bill, since that comprises a big chunk of the budget.
While it's perfectly fine to serve a reception dinner of chicken and not steak to help out the budget, it's still not okay to expect guests to pay for their drinks. You own the day, which means you also own the liquor bill. As loving as your family and friends may be, some may be annoyed if they've got to shell out money for booze. Allotting each guest one or two free-drink tickets should also be avoided. That's not to say you should compromise paying next month's rent so Aunt Jenny can have her heart's content of vodka tonics at your wedding. While an officiant and a marriage license are necessities, a fully equipped bar on your dime is not. Here are some other options.
Limit the bar.
It's perfectly fine to serve just beer and wine, or beer, wine, and a signature cocktail. As long as you give them something to drink that they're not paying for, guests can't complain about the lack of an open bar.
Make the bar non-alcoholic.
Though a no-liquor bar may disappoint much of your guest list, you can turn this drastic option into a win-win by serving fun drinks like a punch.
Go with house brands.
Do the math before ruling out an open bar. Top-shelf liquor would be awesome but it's much pricier than house brands. Most people won't know the difference. Could you swing it if you offered just vodka, gin, and whiskey?
Supply the liquor yourself.
Some venues allow party hosts to buy the liquor themselves rather than have the caterers do it. This means you're not only saving on the per-bottle surcharge can buy liquor whenever you see a sale over the course of your engagement. This could add up to big bucks. It's worth asking your caterer if they allow this policy or, if it's still in the early stages of planning, to seek out venues with a BYOB option.