I would advise against using a flat iron that's that cheap. You should really splurge for a good one, since it's your hair and you'll probably use it on a daily basis.
I suggest the T3 Tourmaline Wet or Dry Flat Iron from Sephora. It's a bit of a splurge $200, but I've only heard great things about the entire Tourmaline line.
http://www.sephora.com/browse/product.jhtml?id=P148412&categoryId=C11244
I second that! I have really curly hair and when i used to straighten it I bought a T3 straightener, they are great and really make your hair dead straight. You need to use a good protectant though!