Cubbies

Trevor and I are going to Chicago in May to stay with his sister Alissa who lives there. We're hoping to go to the Cubs game Friday, May 16th at 1:20 p.m. vs. Pittsburgh. I've found tickets on www.gotickets.com, but was wondering if anyone knew of another (maybe cheaper!) way to get Cubs tickets. I've heard about the ole' "wait until the game starts and buy tickets out front"trick, but we really want to go so I'd prefer not to rely on that. Let me know if you have any suggestions. Thanks!