From the Tweeter Center – Chicago website:
Jimmy Buffett
August 21, 2003 – 8:00PM
On Sale March 15, 2003 – 10:00AM
$ 65.00 Pavilion
$ 35.00 Lawn
http://www.tweetercenter.com/chicago/events.asp?eventID=54369
http://www.tweetercenter.com/chicago/schedule.asp
Ticket price includes $1.00 charity, $2.50 facility fee, and $3.00 parking
Parking Gates Open: Central Time
Concert Gates Open: 6:00PM Central Time
It is also listed on the Clear Channel website: http://cc.com/artist.asp?artistID=24613