One of the biggest costs of a wedding reception, besides dinner, is the cost of an open bar. Some people choose to do a cash bar or place a limitation on how long the open bar is available before converting to a cash bar. However, as the host of the reception, you should avoid anything that would require your guests to have cash on hand. They are, after all, your guests, and asking them to essentially help pay for the party is bad form.
A much better alternative is to limit the bar options to beer and wine. There are several really decent wines with low price tags, such as Cavit, Barefoot, and Rex Goliath. You can purchase beer from a distributor for less than a dollar a bottle. If you really want to limit your bar costs, limit the options rather than making guests shell out their own cash. Nearly everyone will be able to find something he or she likes with a beer and wine selection.
Also, keep in mind that most liquor stores and distributors will permit you to return alcohol that is not used. Ask before you purchase, so you can make sure this is an option. Then you can buy a little more than what you need, just in case, with the option of returning the excess booze afterwards. Your caterer can help you determine how much you need.
*This article is part of a series describing the various steps to take in order to produce the kind of wedding that people will talk about for years. Below are links to other articles in the series.
Planning an epic wedding reception - Part Two: The Toasts