I just wanted to mention one thing--please be careful about buying concert tickets on ebay. If you are going to pay above face value anyway, it would be better to get the tickets through a legal ticket agency--you'll still pay through the nose, but at least that way you won't have to worry about the tickets being counterfeit.
Just as an example, when U2 came to Boston for the first leg of their last tour, staff had to turn away at least 100 people who showed up to the Fleet Center with tickets they bought off ebay--all fakes. It happens all the time.