I source mine from GAP. They regularly have 40% off of their full price which is typically $60.
I'm rocking their slim as well as skinny fit stretch khakis at the moment to work. Passable for semi-formal and darn comfy with the stretch fabric. I don't even need to iron them, just cold wash hang dry. Its wrinkly, but I fold and shelf em which reduces the wrinkles, and when I sit with em on the train, the stretch fabric pretty much removes all the wrinkles by the time I get into office.