Having an open bar at a wedding reception means guests may order as many drinks as they wish at no cost. The bride and groom pick up the tab. This is the type of perk that really runs up the costs of weddings, depending on things like where the reception is held; whether top-shelf liquor is provided or only beer, wine and soft drinks; how long the bar is open; and who supplies the booze, the vendor or the bride and groom. According to WhatItCosts.com, you can expect to spend between $15 and $35 per guest, not including taxes, tips and other fees. According to a survey by The Wedding Report, an industry group, couples spent an average of $2,463 on bar service in 2011, up 12% from the $2,207 spent in 2010.