I think at that age, buying a fancy expensive bat is not all that important. Far more important is buying a bat of the correct length and weight. A seven year old, depending on his size, should be swinging a 28 or 29 inch bat. I would recommend a 29. The next thing to consider is the "drop." That is the difference between the length and weight of the bat. In other words, a 29 inch bat that weighs 17 ounces has a drop of 12. That is what my skinny nine year old swings. When shopping for a bat, have your child hold it at the end of the bat, at the knob, and see if he/she can extend it parallel to the ground and hold it in that position for about five seconds without his arm trembling, or his back arching. If that happens, try a bat with a bigger drop.