The flat iron (aka top blade, top chuck, oyster blade) is a special cut from the shoulder that offers surprisingly good flavor and tenderness at a great price. 
 
What makes this cut so affordable is that it requires a little butchery work before it can be cooked.  A layer of tough silverskin runs through the center of the flat iron, separating two sections of tender meat.  If you're willing to do the butchery yourself (see the Recipes & Tips tab for a video guide), you can have flat iron steaks at a superb price.