$50 for the switch isn't that expensive given (a) it's WiFi controllable; (b) there's not much in the way of alternatives; and, (c) it's consumer focussed.

Prior to the WeMo your best option for power socket control (as an amateur/DIY/Maker) was something like one of these:

* http://www.sparkfun.com/products/10747

* http://www.pwrusb.com/order/

Or hacking a radio remote-controlled power socket. All of which require additional work.

I'm waiting for a 240 Volt version with NZ connectors.