If a person is a first time offender, it's okay to post bond for the person if you trust them to appear. You don't specify what the charge is, but you listed it in the DUI category--- so if the offense is a first time DUI it will be classified as a misdemeanor level offense.  This means that even though it is still a serious charge, it won't carry the most serious of punishment ranges.However, if you can afford to contact a lawyer before posting bail, it could save you some money.  Many jurisdictions have bond guidelines for certain offenses.  If your friend's bail is extremely high, he may be able to get the bond amount reduced, thereby reducing the amount you would have to dish out to a bondsman.The most important thing to keep in mind, however, is that once you put the money down, you are counting on this person to reappear.  If they do not appear as required, you would lose your interest in the bond-- even if you didn't have anything to do with his lack of appearance.