I realize the sale is over, but for future reference with Whole Foods: read the fine print and quiz the dude behind the counter carefully. In my area, the beef they have is grass-fed, but it is not grass-finished.
For only $1 more a pound (everyday price), I can get truly grass-fed/grass-finished ground beef at Trader Joe's.
There is a poster here who used to work for Whole Foods, and he confirmed that they advertise grass-fed, but it is actually grain-finished.
Maybe your region is different. Check.
"Let food be thy medicine and medicine be thy food." -- Hippocrates