FEASIBILITY 315Mhz RF link kits - with encoder and decoder

Hi, I am looking into using the 315Mhz RF link kits - with encoder and decoder kit for simple on/off control of a relay remotely. Can this pair be utilized via MCU–>transmitter><-----><-----receiver—> for cheap and simple control. Is there a cheaper option out there? Also, can multiples of these be utilized in a from one MCU to control multiple devices?
Here is the link:
http://www.seeedstudio.com/depot/315mhz-rf-link-kits-with-encoder-and-decoder-p-151.html?cPath=139_140

maybe you are interested in this …
http://code.google.com/p/rc-switch/wiki/HowTo_Send?tm=6

Regards