My grocery bill more than doubled when I started eating healthy.
If you really want to eat healthy, and have astromonical grocery bills, I believe Gweneth Paltrow's healthy living cookbook has some bland recipes with expensive ingredients.
At least from what I remember of a review of same a few years ago.
Keep a big container in your fridge of chopped purple cabbage, green cabbage and broccoli. All cheap vegetables, all low cal, high fiber, high vitamins. Douse with balsamic salad dressing and dig into it whenever you want an instant salad.
Couldn't be better for you or less expensive.