Tower Garden by Juice Plus: Has anyone used this?

I have several more questions:
1. The pump needs to be plugged in. How much more electricity is it going to cost each month?
2. The food liquid thing lasts around 8 weeks. How much is it going to cost to buy more (+ shipping)?
3. Do the plans such as tomato, cucumber, and kale last forever, the way they do in conventional gardens, where you just pick the produce off to eat, and the plants keep growing? I live in Hawaii, so I can keep it outdoors all year long.