Opinions on kegs at weddings?

A friend of mine is getting married in July. She is trying to go low budget but would still like to have the option of alcohol...The question is, Is it possible to have a keg without a bartender without looking too tacky? All the alcohol would be self serve. She is also considering buying bottles of liquor and allowing guests to pour their own drinks( I think that part sounds tacky) Any opinions would be appreciated.. Thank you!