I've been looking to buy the Derek Jeter Hit-A-Way system for my daughter. Some of her teammates use it on a regular basis, and their swings have noticeably improved. It sells for about $150 at Sports Authority. Even with a coupon, it would still cost at least $120 + tax (and shipping if you order online). I found it on Amazon for much less plus free shipping:

Derek Jeter Hit-A-Way Baseball System (no longer carried on Amazon)


Similar item:
SKLZ Hit-A-Way Portable Training System

Hit-A-Way Baseball System comes with everything you need to start training. Improve your hand-eye coordination with this training aid that works as your own personal batting instructor. Easily adjustable to hit high, middle or low balls. You can also practice switch hitting. Improve swing mechanics without chasing balls. Hit-A-Way Baseball System comes with Hit-A-Way Baseball and movable pole. Ages 7 and up

Product Features
- Improve pacing, timing and confidence
- Develop better swing and stance mechanics
- Learn how to switch-hit
- Ideal development tool for coaches and kids
- Easy to set up for hours of use