For my VX, it was $45. I have no idea what it would cost for your truck though. You can check on Napaonline.com though. Enter in your vehicle and then do a search for "engine heater" without the quotes. Or you could always call up your local Toyota stealership. I know that for the Prius and Yaris that the block heater is a pretty quick installation and it a no mes deal since it just slides into a pocket on the block.
EDIT:
Did a little searching for you....Napa has a frost plug style heater
HERE for $36.