I used to buy tickets online ahead of time but on our last trip we went rather last minute so I waited until we arrived and got our tickets at the purple building on the strip where you can get them for 50% off. No tours or anything required. They are located at the beginning of the strip kind of close to highway 65. They have tickets to almost all the shows. You can look online at the show schedule and list they sell but you have to buy in person. Have fun!!
Branson2for1tickets.net