Zigbee and arduino communications

I suppose you read wrong. I never put the price on the post, and I find them at 5-10 $ in ebay.
Okay so returning to my original question. If I can't control those devices with XBee. What I need to do for controlling the lights of my house and the electrical outlets. Do I have to change them or add something so they can work with XBee?

Thanks for your time.