I don't know about the Knit Picks crochet hooks, but I know you can buy Boye brand at Michael's with a coupon or Joann's or maybe even Walmart for a lot less than that. There are lots of tutorials on tunisian crochet around. I have a few on my own website too if you'd like to take a look. They can be found HERE
in the list of video tutorials.
I always like to invest as little money as possible when trying out something new, then if I really like doing it, I'll go for the more expensive or better quality tools.