I think Sanchez is a pretty good sleeper and he would have a lot more value is the Giants offense wasn't so, hmmm, offensive. A K per inning is certainly possible with Sanchez and having half of his starts at AT&T Park can only help him. The WHIP, however, is a different story.
Sanchez fastball sits around 90-93. He also has a pretty good changeup. On the other hand, his slider is very inconsistent. I'd keep an eye on him at the start of the season, it's not everyday we see a pitcher who can get a K per inning.
I have Sanchez in a 16 team league for a buck, but I will probably sit him the first and second outing to see how he does before I give him the chance to kill my WHIP.