Controlling house current with a pc takes some specilized software and hardware. If you are wanting to purchase a kit, 62 bucks isn't bad at all.
Typically speaking you need an avr hooked to you pc, similar to a ledwiz to pump out the signal. Then you need a transmitter, a number of recievers, and a relay at each reciever.
There are x10 kits periodically on ebay (NEW) that come with just one reciever, and you can get an additional one for 10-20 bucks. But those kits usually run around 35, so 60 bucks for one with multiple recievers that's a good deal.
It's also about as cheap as you can get unless you build the entire thing from scratch.